The third term has begun, and a new homeroom teacher has been appointed to class 5 and 3 at Takehaya Elementary School. His name is Toshihiko Ochiai. When Hiroshi and his five friends saw his face, they were shocked. It turns out that Ochiai is the suspicious man who was following Hiroshi's activities and taking notes yesterday. However, it was also true that Ochiai had a mysterious charm that set him apart from other teachers.

The monster Matenro, who was supposed to be a fictitious entity, actually appears and steals Hiroshi's precious computer. Matenro challenges Hiroshi to win in a battle of wits against him if he wants his computer back. Yasuko couldn't believe what Hiroshi was saying, but she too encountered Matenro, who appeared dashingly in a car of light.

Hiroshi and the five of them form the detective team "Hadogumi" to take on Matenro's challenge. However, as they are elementary school students, they are busy with homework and other things, so it seems difficult to concentrate on their activities as Hadogumi. Just as they are already facing these worries, Ochiai-sensei comes and invites the five to play hide-and-seek. The five people hid under a manhole, but...

Hiroshi and his friends suspect that Matenro's true identity is Ochiai Sensei, and begin investigating Ochiai's background. However, Ochiai is a completely dull man, and even if I'm mistaken, he doesn't seem to be Matenro. Matenro appears in front of the Hadogumi, who are disappointed that their attack has failed. He asks you to come to a Western-style mansion tonight that is rumored to be a "monster's mansion" and steal the treasure, but...

Susumu is about to jump off the roof of a building!? Hiroshi and his friends run to the school, worried that she intends to commit suicide. But Susumu just wanted to fly. Although this commotion ended successfully, information that Matenro appeared at the Space Rocket Research Institute comes in. Matenro dodged the pursuit of the police and flew into the sky!

Today is Hiroshi's classmate Kananari Senkichi's birthday. The five members of the Hadogumi attend a big birthday party held at Senkichi's house, but the presents they prepare are too common and are made fun of. Five people are disappointed. However, at that time, an invisible man appears at the party venue!? He steals the Kananari family's treasure!

Susumu witnessed a housewife, a regular customer of her parents' greengrocer, shoplifting from the store. Susumu tells his father about this, but his father refuses to criticize the housewife's actions. Why is his father silent when his important items are stolen? Susumu, who is not satisfied with this, fasts to show his resistance to his father. However, when he came home one day, something strange happened to his father!?

Satoru suddenly began to wonder how many suckers there were on the octopus' legs. Then Matenro appears and provokes Satoru, saying, "You don't even know about that?" An angry Satoru decides to investigate using an actual octopus, but Matenro steals all the octopuses in Tokyo to prevent Satoru from investigating. What will Satoru do when he is blocked in all directions?

On the way home from school, Yasuko stopped by the botanical garden with Mr. Ochiai. However, Yasuko is disappointed by Ochiai's lack of delicacy. In her heart, a feeling similar to the admiration for Matenro, who always behaved like a gentleman, was growing in her heart. Inspector Karakiri of the Tokyo Metropolitan Police Department appears in front of Yasuko. He was chasing Matenro's crimes.

A videotape was delivered to Hiroshi by Matenro. When they immediately play the tape at the Hadogumi's hideout, they see that it is a criminal notice from Matenro. It is said that he will obtain the "Golden Manju Kannon" at Chikurinji Temple within the day. So, when Hiroshi and his friends asked the Western-Chinese priest of Chikurinji Temple, it seems that the "Golden Manju Kannon" does indeed exist somewhere in the temple...

Hiroshi, Yasuko, and Susumu, who found the "path to the future," disappear. Maybe he was kidnapped by Matenro... While Mr. Ochiai and the three parents were worried, the three in question ended up in the world of 2007 AD. During this period, severe food shortages occurred due to droughts occurring all over the world. Everyone was suffering from hunger.

The world of 2007 A.D. ruled by Matenro, where Matenro turns weak humans into robots and feeds only the strong, or chosen ones. Hiroshi and the three others are finally captured. However, Masao's efforts to communicate with the past world at the request of the three bear fruit, and Takeo and Satoru also arrive in 2007. Now is the time to strike back!

Today, Satoru is on duty to take care of the weapons of the Hadogumi. I had just witnessed Mr. Ochiai making a phone call somewhere, so out of a sense of mischief, I turned my "shoe-on-ser" on and could hear what Ochiai was saying. The teacher is Matenro after all!? Satoru chases after the teacher in order to get definitive proof, but not only does he lose sight of him, but he also breaks the shoe-on-ser...

A burglar broke into Senkichi's house. Fortunately, Chikichi was not injured, but Mr. Ochiai takes this incident as a lesson and tells the students, "When in danger, run away first." The following Sunday, Takeo's father left for Shinshu. Since his father will be away for about a month, Takeo decides to protect his mother in his place. However, Takeo's feelings were a little too strong...

Yasuko sees a magic show by Ten-O, a world-renowned magician, and becomes inspired to become a magician. At the school newspaper's editorial meeting the next day, Yasuko proposes a special feature on magic. He attempts to interview Ten-O himself. However, in reality, Ten-O was a suspect marked by the International Police. According to Inspector Karakiri, Ten-O might be Matenro!?

Hiroshi, who has been playing games at home, realizes that he forgot his homework at school. Hiroshi's father also scolds him, so he goes to pick up his homework even though it's late at night. Then, the vice principal was crying alone in the staff room... In fact, there had been an incident at Takehaya Elementary School where someone had stolen the grades of the upper grades. The vice principal was suspicious of Matenro.

At Yasuko's suggestion, the members of the Hadogumi decide to go cycling. One of the goals is to deepen the friendship among the team. The other was to offer oil to the "Bicycle Shrine" at the request of the owner of the bicycle shop. Yasuko finally arrives at the bicycle shrine, where she is suddenly attacked by bicycle parts. Yasuko is in danger!

Hiroshi was popular with the girls at school. The reason for this, according to Hiroshi himself, is that his "transparent kindness" is effective. In other words, it was all a calculation. Matenro steals Hiroshi's "kindness". Hiroshi loses his "kindness" and suffers. What's more, Matenro orders Senkichi to take away her family's jewels as a condition for returning his kindness.

A series of kidnappings of elementary school students occur. Mr. Ochiai lectures his students on the despicable crime of kidnapping and the mental attitude children need to protect themselves. However, Hiroshi thought that this incident should be resolved by the Hadogumi, so he called the members together after school. The members agreed with Hiroshi on the condition that he would not do anything dangerous. The activities of the Hadogumi begin.

The Hadogumi group is in danger due to the mysterious kidnapping group, the Darkness Clan. The Dark Clan's goal was to find a boy with the perfect talent and have him rule the future of Japan and eventually the Earth. The family is finally deciding on a prestigious successor through a selection test. Hiroshi and his friends were also made to participate in this test. What will be their fate?

The training camp for the Hadogumi has begun. However, on the morning of the second day, Susumu collapses. Surprisingly, Susumu can't sleep unless he listens to his mother's lullaby, and he couldn't sleep at all last night. Susumu is embarrassed when his friends find out his secret. And, as expected, even Matenro found out about the secret. Matenro declares to Susumu that he will steal her lullaby.

Inspector Karikiri and Takeo's father, Shoichiro, were childhood friends. The two meet again for the first time in a long time, hit it off, and have a drink at Shoichiro's house. Shoichiro had just discovered some earthenware in Shinshu and brought it back with him, so he earnestly asked the Metropolitan Police Department to have it examined in detail. As a result of the appraisal, it was determined that the pottery that Shoichiro discovered was a national treasure.

Takeo is obsessed with bird watching. He was flapping in the early summer sky, staring at the birds with sparkling eyes. However, there was a group that was targeting these birds with a slingshot. They are students from another school, the Pachinko group. Takeo protects the bird from them and ends up getting injured. Hiroshi and his friends hear this and decide to take revenge on the pachinko group.

Because Satoru's mother is not feeling well, the restaurant run by Satoru's father has to temporarily close, even though it is Sunday. So, Hiroshi and his friends use this opportunity to make a plan to have Ochiai-sensei and Junko-sensei go on a date at a restaurant. However, the person who came to the store was Matenro, not Ochiai. He offers a "date truce" to the Hadogumi.

In order to capture Matenro, the special training of the Hadogumi continues. However, Yasuko's special training menu was difficult for Hiroshi and his friends. So they consulted Mr. Ochiai. Ochiai called Yasuko and told him to think about the contents of his special training. However, on the way home, Yasuko suddenly travels through time and space to a mysterious village. Yasuko is asked by the villagers to exterminate the White Bone Princess...

Susumu encounters a flying saucer on her way to the Hakuan's hideout. However, none of his friends believe Susumu's story. Susumu is disappointed, but when he tries to sleep that night, an alien appears in his room. The alien came to Earth to sell "Diamond Flower Seeds" to Matenro. However, Susumu ate the precious seeds.

Yasuko receives a call from her classmate Kurumi that her life is being targeted, and goes to the mansion where Kurumi lives with Hiroshi. Kurumi was in a traffic accident on the day of her first day of school and has been absent from her school ever since. After hearing the details from his girlfriend Kurumi, Hiroshi summons the remaining members of the Hadogumi to the mansion. Is Kurumi's life really being targeted?

Susumu's desire to become a ninja escalates day by day. As Susumu continues his solitary training, Iga-ryu ninja Madara no Hanzo appears. Susumu immediately becomes Hanzo's apprentice. However, at the same time, a thief who commits crimes using ninja-like techniques appears and causes a stir. Hiroshi and his friends suspect that Hanzo, Susumu's master, is the culprit, but...

Summer vacation has arrived. Takeo and Satoru have a disagreement over where the things that Matenro stole are hidden, and they end up fighting. Frustrated, Takeo begins investigating the incident on his own to prove that his opinion is correct. Taking full advantage of Shuonser and Kinmikkel, Takeo arrives at a certain factory. But he gets caught by a gang!

Hadogumi continues training to capture Matenro. However, in the middle of the training, the real Matenro appears. Everyone chased after Matenro, but Hiroshi took action on his own from the middle. Matenro then praises Hiroshi's courage and treats him to a sumptuous meal. Furthermore, Matenro continued to give Hiroshi what he wanted one after another. What is Matenro's aim?

Mr. Ochiai brags to Hiroshi and his friends about his old "kidameshi." Frustrated, the five members of the Hadogumi decided to surprise Ochiai by planning their own liver attack. Ochiai invites Junko-sensei, and then the Hadogumi invites Senkichi, and tomorrow is the day when they will lose their nerve. At that time, Matenro appears in front of Hiroshi and his friends and issues a "warning" to them, but...

Crimes in which young women were slashed in the face were occurring one after another. Ochiai-sensei talks to the members of the Hadogumi about the special psychology of these "pleasant criminals" and the "spiritual spring" that humans need to survive. Hiroshi and his friends are impressed. However, Ochiai-sensei himself has been dumped by Junko-sensei many times and seems to be losing the spring in her heart. So Takeo tries to support the teacher.

The members of the Hadogumi went camping during their summer vacation. Hiroshi and his friends look back on the days of their battle with Matenro. If you think about it, Matenro should have been a fictitious existence in the first place. However, when he actually appeared, the Hadogumi was formed and continues to this day. Matenrou is an existence that I will have to overcome someday. The five people changed their minds.

The second semester has begun. However, Hiroshi and Susumu had not finished their summer homework. So Ochiai-sensei orders him to stay up all night tonight and finish his homework. And that night. Matenro is seen at Hiroshi's classmate Mamoru's house. Matenro let Mamoru's pet owl escape and stole Hinausu Yukisou...!

A man appears in Hiroshi's neighborhood who drinks nothing but water from morning until night. So, Hiroshi and his friends throw stones at the man's house to make fun of the man, nicknamed the "water drinking man." Naturally, the man chased after me. Hiroshi and his friends successfully escaped. However, a housewife who witnessed this act has already reported it to the vice principal, who harshly reprimands them.

Today is an outdoor class. Usually I do a lot of sketching, but at Mr. Ochiai's suggestion, I decided to do a special "treasure hunt". As a member of the Hakuan-Anou group, we couldn't afford to lose to our classmates, but the other teams continued to find treasures. Unfortunately, the time ran out, but at that moment, Kinmikkel, which Satoru and Takeo were using, reacted!

While jogging in the morning, Satoru happened to see an old gentleman who appeared to be Matenro in disguise. Satoru tails the old gentleman. Unfortunately, he escapes, but the Hadogumi uses Satoru's information to set out to locate Matenro's hideout. Satoru was especially excited, but his enthusiasm backfired and he was captured by Matenro. What will be Satoru's fate?

Susumu falls in love at first sight with a beautiful girl he bumps into in the school hallway. Knowing this, Hiroshi and his friends rely on the ballpoint pen that the beautiful girl dropped and begin to investigate who she is. As a result, the beautiful girl turns out to be Yuki Watanabe from Group 1. Although she only recently transferred to the school, she was already so popular that she had many fans. Susumu wants to convey her feelings somehow...

A Western-Chinese priest of Chikurin-ji Temple was appointed as the head priest of the head temple. Hiroshi and his friends immediately congratulate the westerner. Hiroshi is impressed by the humble Westerner's attitude of continuing to interact with him as before even though he has been promoted. However, that is only on the surface... The Western man, who was so happy in his heart that he wanted to jump at any moment, was devising a plan to add foil to his career.

Inspector Karikiri was summoned by the Superintendent General. Just when he thought his hard work had been recognized and he was finally getting a promotion, he was disappointed when the general manager suggested he change jobs to a beef bowl chain. This made Ikan even more determined than ever to arrest Matenrou, but his actions were no longer normal. Susumu, who casually encouraged the inspector, feels a strong sense of responsibility, but...

Today is payday for Hiroshi's mother, Hiroko, who works part-time. Hiroko stops by her department store and witnesses the moment of Matenro's crime, and immediately after that, Dr. Ochiai. As expected, Matenro is Ochiai-sensei!? Meanwhile, Hiroshi and his friends are concerned about Matenro's recent movements. Perhaps he plans to earn some money and flee overseas soon?

Hiroshi became Matenro's servant in order to save his mother, Hiroko. When Hiroshi hears from Matenro that his purpose is to create a kingdom for children, he becomes interested in the story, but Matenro tells Hiroshi to come and punish the members of the Hadoumi. Command. Hiroshi disobeys Matenro, saying he cannot betray his friends. At that time, Yasuko was formulating a strategy.

A family restaurant opens near the restaurant "Bonbon" run by Satoru's father. Since then, the number of customers has gradually decreased from Bon Bon. Satoru is worried that if things continue like this, he might not be able to run the store. One day, a customer visits Bonbon. The appearance is just like the jewel robbery shown on TV!

Hiroshi and Yasuko are still good friends. However, Susumu, Satoru, and Takeo also thought about Yasuko in their hearts. Takeo worries that he can't beat Hiroshi in terms of face. There, Takeo tries to shake off his doubts by playing sports, but when he comes to, he is in the "Mangetsu Tanuki Palace". When Takeo is asked for help by a "raccoon princess" who looks exactly like Yasuko, he becomes completely interested in her...

One night, Hiroshi went to deliver a letter that had arrived at his house by mistake to the correct address. Then, by chance, he discovers Matenro at that house. Matenro entered the house and descended the stairs leading to the basement. There was a roulette hall in the basement. Matenro steals the money used for gambling and runs away. Hiroshi chases after him, determined not to let him escape today.

Susumu can't hide his dissatisfaction when his parents force him to take care of a greengrocer. He announces to Ochiai Sensei, who has just visited his shop, that he will spend the weekend in the mountains practicing ninjutsu. When Ochiai heard this, he advised him, "Find your true courage in the mountains." Susumu set off with a bang, but Mt. Kiribuki, which is known for its thick fog, is still a scary place for Susumu...

Takeo has been acting strange lately. He doesn't even try to participate in the activities of the Hadogumi, although he does tell his mother that he's going to their hideout, and his strange behavior stands out. Since her husband Shoichiro is away in the mountains, his wife Hanako decides to consult Dr. Ochiai about her son. Ochiai immediately talks to Takeo. Takeo felt a sense of emptiness in the activities of the Hadogumi.

In an unusual move, Satoru summoned the members of the Hadogumi. The reason was that a woman's screams were recorded on the shoe-on-cer. According to Satoru, the person who screamed was probably a female spy from the East who was targeted by an international assassination team. However, this is just Satoru's fantasy. No one believed him, but Yasuko decided to cooperate with Satoru.

The closing ceremony of the second semester came early. Mr. Ochiai uses the example of plum blossoms, which can withstand the cold of winter, and says that he wants his students to have a strong spirit. However, Hiroshi's conversation made him worried that Ochiai might not come to school again in the third term. As things stand, Matenro's true identity remains unknown.

The final confrontation between the Hadogumi and Matenrou is now upon us. With the help of the Pachinko group, the Hadogumi defeats Matenro's subordinates, and Matenro is the only one left! Hiroshi and his friends also discover the jewelry that Matenro had stolen, bringing them one step closer to victory. Matenro now reveals the "Tower of Light" construction plan. The four of them, except Hiroshi, are moved by Matenro's wonderful vision, but...