Haven't You Heard? I'm Sakamoto

Envious of Sakamoto's popularity, three delinquents, Atsushi, Mario and Kenken tried multiple attempts to bully Sakamoto but failed miserably. In their recent attempt, they accidentally put on a fire on the school laboratory until Sakamoto's quick-thinking skills called Kakuta, a nearby teacher to put out the flame. With Sakamoto took the blame for them, the three delinquents started a liking towards him.

Sera tries to gain more popularity by defaming Sakamoto, which failed. During class session, a hornet invaded the classroom. Sera used this as an opportunity by attacking the hornet but as he nearly endangered, Sakamoto engaged in a sword fight using a compass against the bee's stinger and managed to neutralize the situation without harming it. Having endured the humiliation earlier, Sera decided to become a comedian instead.

With Kubota always lacking money due to being constantly bullied, Sakamoto helped him by getting themselves worked at a fast food restaurant. Initially unable to cope with his workplace, Kubota later takes a liking to it. During his payday, the two bullies that targeted Kubota appeared again but Sakamoto's advice allowed him to stand up against them until Sakamoto arrived and the two fight back against the bullies. Before leaving, Sakamoto complimented Kubota's secret technique and advised him to sharpen it.

The second arc focuses entirely on Aina's attempts to flirt Sakamoto, which ended up in failure, partly due to Yagi and Tanaka. While the three girls played a kokkuri, an they accidentally made Sakamoto possessed by a spirit and ordered the girls to build an arch for him in any form. Yagi and Tanaka uses the students' desk and chair before Aina finally gives into her cooperation out of guilt. As their operation succeeded, both Yagi and Tanaka started to gain respect and befriended Aina before heading home. In the end, it was revealed that everything was orchestrated by Sakamoto himself, having pretended to be possessed all the time.

Maruyama and the upperclassmen delinquents bullied the first years into their servants. One of the servants is Sakamoto, whom Maruyama tried to put him to use, seeing how efficient he is until Sakamoto overwhelms him.

With Kubota's grades falling, Sakamoto helps him study for the next exam. Kubota's mother takes a liking to Sakamoto ever since his first arrival to their house, with that day, Kubota plans to hide Sakamoto in his house. While he walks out to buy some groceries, Sakamoto tries to evade Kubota's mother in the house as quick as possible. Spotting a camera and a disk, he used this as a chance to trick Kubota's mother into thinking that Sakamoto had fled into the television. Following that incident, Kubota and Sakamoto study at the library.

Kakuta, the class' physical education teacher tries multiple attempts to have Sakamoto caught red handed but fails miserably. During the classroom session, he gets this chance when Sakamoto eats in the class but was revealed to be a plot just to feed an injured bird.

In the cooking class, Kana-chan encounters a slug inside a cabbage, which Sakamoto skillfully get rid of. In art class which involves drawing each of the students' partners, Aina pairs herself with Sakamoto. As it seemed that Sakamoto sketches her as a orangutan, it was revealed that she viewed the art in a wrong way and its true form quite beautiful. After a fire broke out in the school, Sakamoto rescues Acchan, whom was left behind in the school toilet after everyone evacuated.

When Acchan and his fellow delinquents accidentally had Sakamoto dropped into their trap, they tried to search him after his disappearances extended to a week. When they only found his button inside the trap, they thought that Sakamoto used Acchan's trap to get to the other side of the world, though later it is revealed that this is not the case, as the hole is actually shallow. Sakamoto entered the trap on his own under the pretense that they are digging for a hot spring, and helped them digging further. The truth is they just didn't see him when he got out.

When it is Sakamoto's turn to throw the softball, Kubota accidentally get hit by the thrown ball, causing a nosebleed. Sakamoto stops the bleeding by ripping off part of his shirt and wrap it around Kubota's head.

Seeing Maruyama's traumatized behavior when they talk about Sakamoto, Hayabusa goes to see Sakamoto. Due to a misunderstanding, Hayabusa thought that Sakamoto orders Class 1-2 girls to assault him when they meet, and is under the impression that Sakamoto has taken control of Class 1-2 students. Hayabusa asks Sakamoto to meet him at the riverbed after school, but Sakamoto declines, as he has cleaning duty. In order to make him go, Hayabusa's underclassmen try to make him angry by stealing his indoor shoes and ruler (which he named Smith), and leaving notes to give the impression that Hayabusa is the one who did it. Finally, upon seeing a bald Kubota Yoshinobu crying, an angry Sakamoto goes to see Hayabusa. As they are about to fight, a police officer sees them, and Sakamoto gives an excuse that they are just playing 手押し相撲 (Teoshi Sumo, literally hand-pushing sumo). Despite claiming they are just playing, Sakamoto has all the intention to beat Hayabusa in pushing sumo, which results in both of them fight a rather serious match. After knowing the truth, Hayabusa and his underclassmen go to Kubota's house to apologize and gives him seaweed to make his hair grow faster, and a happy Kubota throws a seaweed party.

Sakamoto has a fever, and instead of resting in the infirmary, he wears a tie made out of Welsh onion.

Several elementary school students follow Sakamoto on their way home.

Megumi, Sakamoto's stalker and Class 1-2's representative discovered a ghost infatuated to him and tries to warn him. In the end, she graduates from being a stalker to a photographer who takes Sakamoto's pictures.

In the epilogue, Sakamoto helped the lunch lady to promote her neapolitan via subliminal messages.

In a video rental shop, Acchan and friends trick Sakamoto to help them renting adult videos. After manages to avoid being detected by Aina and friends (and Shigemi), Sakamoto face the shop manager at the counter in a bluff act, who suspects that Sakamoto is still underage. When everything is over, Acchan invites Sakamoto to watch the rented videos together, but Sakamoto escapes immediately. Realizing that it is still too early for them, Acchan returns the adult videos without watching them.

During Sports Day, Sera tries to overtake Sakamoto's popularity (or at least, make his popularity lower) by sabotaging the events with the cooperation of the rest of Class 1-2 boys. Despite all odds, the plan backfires on them, as Sakamoto wins the events with style, and his popularity increases as a result. In the relay race, Sera ties both of Sakamoto's shoes so that he can't run. Far from giving up, Sakamoto bites the baton with his mouth and runs like a four-legged cheetah. When he passes the baton, the baton slips from Yagi's hand due to the baton covered in saliva, which makes them fall down to last place. Seeing Yagi cries while running, Sera decides to erase Yagi's mistake from everyone's memory by doing a more memorable event... by running naked after the baton is passed to him, to everyone's gross and dismay, though Yagi thanked him later on.

Maruyama, Hayabusa and upperclassmen delinquents try to participate in their school's Cultural Festival by making cotton candy cooked from improvised equipment. Acchan suggests to Hayabusa that Sakamoto should be invited to their booth and Hayabusa seemingly agrees until Fukase, a long time delinquent with a strange past, interrupts and forces Hayabusa to spill out about Sakamoto. Hayabusa didn't say anything about Sakamoto and Fukase uses the cotton candy machine to hurt Hayabusa. Meanwhile at room 1-2, the class is struggling to make their own booth by using balloons and Sakamoto improvises everything to make their balloon presentations look attractive and convincing. However, two slackers who are seemingly no help to other classmates left the room and sulks about Sakamoto's participation. Fukase approaches them, and suggesting the slackers to do something in order to damage Sakamoto's reputation. The next day, the balloons were destroyed and wanted posters scattered around the campus, accusing Sakamoto who is responsible for the mishap. Now a wanted man, Sakamoto evades delinquents who are trying to get him because of the reward and Fukase quietly watches. Sakamoto decides to clear his name, he went to his rooom and saw the slackers reorganizing their presentation. His classmates convince Sakamoto to admit the mishap but he left. Later, a mysterious girl name A-ko (A子, literally Girl A) knocks on their room and admits she popped the balloons. One of the slackers utters that the girl is lying, but Mi-chan points out that they shouldn't know that as they left early yesterday. When the slacker opens the door, it reveals that Sakamoto is using helium gas and turning the tables against the slackers. The slackers attempts to pop the balloons but Sakamoto cleverly intimidates the slackers by popping the balloons using sunlight reflecting on Kubota's mirror. The confrontation ended when the slackers give up and Sakamoto lectures them. With no time left and lack of materials, Sakamoto uses remaining balloons attached with invitations and Hayabusa's cotton candy to craft Yeti costumes, as they organizes a Yeti Hunting Game. As Sakamoto donning a Yeti costume, they run on the hallway and Fukase looks on Sakamoto which the latter also gazes at Fukase.

Megumi Fujita, along with Kana-chan and Mi-chan, ate their lunch outside and started recollecting on how they first met Sakamoto. Megumi met him at the entrance exam, where he warmed her trembling hands by heating up her fallen eraser with frictional force. Mi-chan met him on the day of entrance ceremony, where the storm broke her favourite umbrella. Firstly sadden, she then cheered up when Sakamoto treated his broken umbrella like a wine glass and acted like a rain sommelier. Lastly, Kana-chan met him during the day before the entrance ceremony. Since she had forgotten her bag, she held all her textbooks in her hands, and as such, was unable to see forward. When she fell down, Sakamoto caught and princess-carried the books. While the girls are smitten over Sakamoto's initiatives, Kubota on the other hand reminisce his first acquaintance to Sakamoto where his bandage on his ring finger fell and Sakamoto returns the bandage seeming like inserting a ring. Sakamoto chides Kubota's story but the girls, upon hearing Kubota's story, felt envious where that moment was the most romantic.

When her son Yoshinobu comes down with a cold, Shigemi Kubota gets another chance to romantically pursue her underage love interest to Sakamoto. Taking advantage of her resemblance to her son, Shigemi dons his uniform and goes to school in his place. Although she has plenty of opportunities to make a move on Sakamoto throughout the school day, Shigemi's efforts are thwarted at every turn. During their athletics class, Shigemi chases Sakamoto but falls down, destroying her shell necklace. Sakamoto picks up the pieces and returns it to Shigemi, realizing that she cannot fulfill her desires to Sakamoto and recollects being a mother to Yoshinobu, resolving to prioritize being a good mother. The next day, Yoshinobu recovers and Shigemi prepares a meal to him.

During Christmas Eve, Sakamoto is invited by two college students to a karaoke in order to complete their number, but seeing how Sakamoto attracted the female audiences, they tried to sabotage his karaoke moment until he covered it via his singing of a famous poem Der Erlkönig.

Hayabusa seeks Sakamoto's help when his father invites him to a fancy dinner with a woman, who he claimed is Hayabusa's stepmother candidate. As Hayabusa has no knowledge about table manners and Sakamoto points out that it can't be learnt in a single day, Hayabusa rents a LL-size coat, in which Sakamoto hides in it and use his hands instead of Hayabusa's at the restaurant. Later, when they found that Hayabusa's father is cornered by some thugs, Sakamoto and Hayabusa change places to fight them. The woman turns out to be an extortionist, and Sakamoto skillfully fends them off by using the opportunity to tell a horror story about a person eating Italian cuisine who grows another pair of arms out of allergy. Hayabusa concludes that rather than pretend that they have something they lack, they should make up for what the other person lacks.

As Yoshinobu walks with Sakamoto to school, he realizes that he knows almost nothing about Sakamoto, though he assure himself that he will have a lot of time to talk about it later. Hearing that it is the first time Sakamoto has seen snow, Acchan teaches Sakamoto how to play in the snow. Frustrated that Sakamoto has surpassed him in everything he taught rather easily, Fukase approaches Acchan, suggesting he fights Sakamoto in a one-on-one battle. He then decides to fight Sakamoto in a snowball fight, determining to crush him. Watching Acchan trembling in coldness, Sakamoto throws a hand warmer to him. He felt bad because despite his intentions, Sakamoto earnestly just want to play, and even thinking about his well-being. As he walk home, Fukase approaches him again.

Class 1-2 reminisce about their memories throughout the year by looking at the pictures taken by Megumi, especially Sakamoto's pictures. Notable events including the day Sakamoto made umbrella arrangements, Marathon Race day, and the day they went to beach. Hayabusa and the other delinquents have a meeting, and he tells them that Fukase is not going to graduate (again) that year. Mario and Kenken points out that Acchan is acting weird lately, and a lone Acchan, holding one of the pictures, gets approached again by Fukase, who persuades him to burn the picture, alongside all his attachment to Sakamoto. In the epilogue, during the graduation ceremony, Acchan walks towards Sakamoto still giving the farewell speech on the stage, telling him to disappear, with a metal bat on his right hand.

Picking up from the previous episode, Fukase converses with Atsushi who persuades him to eliminate Sakamoto by burning the picture and his admiration to him. At the graduation ceremony, Sakamoto initiates the graduation speech by presenting a volleyball he retrieved from above. As he speaks to the crowd, Acchan approaches Sakamoto with a metal baseball bat. Acchan randomly swings his bat against to those who interfere his move and Fukase stops the teachers. With the crowd shocked and thinking it is a part of his presentation, Sakamoto extends his speech as he evades Acchan's attacks until they reach the rafters. Acchan sways his bat again but slips down when Sakamoto quickly grabs his hand. However, Acchan swings his bat to Sakamoto's hand and berates him about looking down on his personality. A wounded Sakamoto improvises his speech and tells everyone including Acchan about believing with friends. Acchan slips his hand and Sakamoto still catches him, proving that Sakamoto had deep care on his friends. The crowd seems delighted and gives Sakamoto a standing ovation. Acchan surrenders while Hayabusa's group arrive. Sakamoto heads to the clinic to tend his wounds and sees Fukase for the first time. Fukase compares himself to a deep ocean while Sakamoto, filling with hope, sees himself that he will swim that deep ocean to find new opportunities. Hayabusa, determined to put an end to Fukase, waits outside while Sakamoto approaches him and suggests a non-violent way to eliminate Fukase. As the graduates march with Fukase looking on, Hayabusa and his group enters and "congratulates" Fukase. With the help of Sakamoto, Fukase is being thrown out in the graduation ceremony. Kubota narrates the aftermath of the ceremony, Acchan was unpunished believing that he was part of Sakamoto's presentation, Fukase was seen on a beach holding a surfboard and a rumor found to be true which is Sakamoto leaving. Sakamoto was selected by a space administration in America and he will pursue his studies to become an astronaut. The 1-2 class bids farewell to Sakamoto by means of pie throwing which Sakamoto easily dodges as he leaves the classroom and holds a single pie on his hand. Hayabusa also bids goodbye to Sakamoto. At the school gate with Kakuta guarding, Sakamoto approaches with smothered pie on his face. He is being asked and he simply says, he is Sakamoto.

Following Sakamoto's departure, the students come up with different ideas for making a Haven't You Heard? I'm Sakamoto movie. Later, upon finding photographic evidence of Sakamoto being in America, the students try to imagine what he is up to, ranging from training to be an astronaut to being a student at a martian high school. Meanwhile on America, Sakamoto was enlisted as a shuttle pilot and was able to hinder a leakage in the fuel, therefore successfully bringing the shuttle back to its track.