Yoshifumi Aoki/Story Plot

Spoilers below

Hito Random arc
In the dead of night, Aoki awakens to find himself in an unknown bedroom. Nothing in the room is familiar to him, in fact, the room is full of girly accents. Upon inspecting a mirror, Aoki, to his surprise, finds that he resembles his friend and crush, Yui. Confused, Aoki hides under the bed sheets, and suddenly, he finds himself back in his own room and body.

The next day at school, Aoki discusses his bizarre "dream" with Yui who claims to have experienced the same thing. They relay their experience to their friends at the Student Cultural Society but none of the others believe them and even Yui starts having her doubts. However, after Taichi and Iori switch bodies themselves, Aoki is all but certain that they are indeed somehow swapping bodies, though no one understands why.

The next day, after several more swaps occur, the group is confronted by a mysterious being by the name of Heartseed, who possesses their club advisor, Gotou. Aoki can only watch as Heartseed explains that the StuCS will keep switching bodies until he is adequately entertained. Though faced with an impossible situation, Aoki does his best remain his normal, goofy self, not wanting his friends to lose hope, and trying to enjoy life as best he can under such conditions. Not disheartened by the phenomenon in the slightest, Aoki would later take the time to confess his love to Yui. Yui turns him down, but muses that she's not ready yet to be in a relationship, which gives Aoki hope.

Later, when Iori is critically injured at Heartseed's hands, Aoki and the others are given the chance to save her, but one of them would have to give up their own life in Iori's place. Though it wrenches his heart to say it, Aoki suggests Iori be the one to die with her body, an opinion Iori herself agrees with. He later allows Iori to use his body to communicate her final messages to her friends before she dies. To his elation however, Iori survives her ordeal and Aoki later celebrates with the rest of the StuCS when Iori returns to school.

Kizu Random arc
Following Iori's recovery, Aoki and the rest of the Cultural Society enjoy a brief time of peace, that is, until he and Yui return to the clubroom one day to find Inaba imposing herself onto Taichi. Yui flips out at the sight, smashing the club table in half, and Aoki is left dumbfounded at the madness around him. On their way home, Yui is arrested by the police after impulsively attacking some boys and Aoki ends up in a scuffle with an officer, commanding they let her go. Confused by why he suddenly started acting so rashly, Aoki allows himself to be taken into custody, but luckily he is let off with a warning. .

The next day, Aoki and the others are informed by Heartseed that a new phenomenon is occurring that forces their desires and impulses to go unrestrained. Aoki is outraged by how Yui has suffered due to Heartseed's intervention but manages to keep his temper in check by simply thinking of Yui.

After Yui refuses to return to school out of fear that she may hurt more people due to her impulses, Aoki and the others visit her at her home. The StuCS tries to counsel Yui, but their plan fails when Inaba's impulse unleashes and she harshly berates Yui for her cowardice. Aoki and the others plan to continue reaching out to Yui until she comes around, but when Yui insists they stop visiting her, they begin doubting themselves. . Desperately wanting to help Yui but having no idea how to go about it, a stressed out Aoki has a bitter argument with his best friend, Taichi, who berates him for his uselessness and Aoki, in turn, accuses Taichi of only wanting to help Yui to fuel his own ego. The fallout that occurs leaves both friends ashamed of their actions and insecurities. .

Later, a remorseful Aoki plans to apologize to Taichi but is infuriated when his friend asks for Aoki's forgiveness first. The two make amends with one another and Aoki figures out how he can help Yui. Returning to the Kiriyama residence, Aoki announces to Yui that even if her violent impulses are unleashed, she can control herself through sheer willpower and to prove his case, Aoki invites her to a love hotel, though Yui is less than enthusiastic. Her confidence restored, Yui agrees to return to school but asks Aoki and Taichi to protect others from her if anything happens. Aoki insists Yui rephrase her request and Yui asks Aoki to "please protect [her]." Like a knight in shining armor, Aoki kneels before his princess and accepts the responsibility. .

Aoki would later attend his class field trip with Yui and the rest of the Cultural Club. Throughout their trip, Yui worries how the others are doing but Aoki, keeping with his carefreeness, insists she not worry and to enjoy herself. Later, after the phenomenon ends, Iori and Yui muse how they anticipate Heartseed will strike again, but Aoki declares they should enjoy their freedom while they can and happily leads his friends back home for a much deserved rest. .

Kako Random arc
With their second semester as 1st years over, Aoki and the rest of StuCS look forward to their Winter Break. However, to Aoki and the others' distress, it is revealed that a new phenomenon is occurring that physically and mentally reverts the club members to various ages. Taking refuge in an abandoned building near Inaba's house, Aoki himself is later reverted to a child. While in his adolescence, Aoki mistakenly confuses Yui with Nana, Aoki's first love from junior high. Even after he returns to his proper age, Aoki retains his memories and feelings for Nana, which makes him question everything he knows about loving someone. Eventually, Aoki remembers his old philosophy of always living life carefree and resolves to find and speak with Nana to put his past behind him and Taichi offers to accompany him. .

Aoki reflects how when he was in junior high, a classmate of his died in a car accident, which greatly impacted him. Ever since, Aoki, realizing how fragile life is, took an oath to live every day carefree so he'd never have any regrets. When Aoki finally tracks down Nana, the two greet each other like old friends. Aoki admits that while he loves Nana, he now loves someone else even more. Having patiently listened to her former love's honest feelings, Nana acknowledges and Aoki returns home, his heart at peace and now able to look toward the future.

Aoki returns to the abandoned building where he once again expresses his love to Yui, reaffirming that she alone is most worthy to own his heart. Yui, touched by Aoki's creed, decides to start taking control of her own life, starting with her androphobia. Determined to stop running away from her fear of men, Yui tightly embraces Aoki. Aoki remains perfectly still and allows Yui, with her own strength, to finally overcome her androphobia. .

Later, Aoki would assist Iori in solving her family matters. .

Michi Random arc
With their final semester as 1st years having begun, Aoki is determined to make the most out of everyday, but Heartseed has other plans for him and the Cultural Society. Heartseed initiates a new phenomenon that forces random telepathic communication between the club members, though the club remains confident that they will overcome the phenomenon like the rest. Aoki in particular is unfazed, insisting they turn their attention towards celebrating Valentine's Day. Through a string of telepathic transmissions, Aoki learns that Inaba has a crush on Taichi and that Taichi has confessed to Iori but was turned down. When Inaba starts an argument with Iori, Aoki receives telepathic transmissions from Iori that show a darker side of his President that he's never seen before. . Things get worse when Iori chooses to abandon the StuCS, feeling judged after hearing all their negative transmissions towards her. Aoki desperately tries to stop her from leaving by cracking a joke in his usual manner, but Iori ignores his attempt and turns her back on the club. Returning home, Aoki is confronted, alone, by Heartseed who calls him the most useless and boring member of the group. Aoki insists that he can help others by being himself, but Heartseed rebukes that being himself is the same as doing nothing. Just as Aoki begins to doubt himself, he receives a transmission from Yui who wonders how he is doing. Suddenly brimming with confidence, Aoki declares that even if he's useless, so long as Yui cares about him, he can keep fighting and will never give up. .

Later, Aoki and the others find their clubroom vandalized and their end of the year club presentation destroyed, courtesy of some thugs hired by  Setouchi in her vendetta against the maverick Iori. Aoki is ready to lose hope, but after some reassurance from Taichi, he and the StuCS are determined to rebuild their presentation better than ever. Aoki later receives a transmission from Inaba, who pleads for help after having been abducted by the clubroom's vandalizers. .

Meeting with Taichi and Yui, Aoki manages to find the warehouse Inaba is being kept at and together, the three subdue most of her abductors. However, when Inaba is held at knifepoint by one of the thugs, Iori steps in. Pretending to assist the thug, Aoki is fooled to believe Iori is betraying them, but is relieved when her gambit works and Inaba is saved. Aoki later witnesses Iori take her "revenge" on Setouchi only to forgive and befriend her.

Aoki later helps give the club presentation and his fantasy for the girls to cosplay while giving it is realized. Afterwards, Aoki watches as Inaba attacks Gotou for choosing to be advisor to both the Cultural Club and the Jazz band club, completely disregarding their efforts with their presentation. Aoki would later retake his finals after failing the first time. He prepared for it diligently with the help of Yui, whom Taichi thinks is warming up to Aoki, slowly but surely. .