Futaba Mikuriya arrives as a transfer student at Minagami High School, returning to Japan after living abroad. He joins the Hero Club, presenting an initial facade of fashionable normality that masks significant secrets. Beneath this carefully constructed image lies a self-absorbed, narcissistic personality. He covertly achieves online fame as the tone-deaf singer Kirito Setsuna on Nikori Video while simultaneously hiding his passionate otaku identity, reluctant to reveal his true self.

His connection to Rei Tsukumo holds a hidden layer: they are cousins who share knowledge of each other's secrets yet maintain a deliberate pretense of being strangers at school. Among the Hero Club members, Mizuki Hijiri initially views him as the sole normal person, a perception that shifts only after he confesses his otaku nature. He addresses Mizuki by her first name, explaining this habit stems from his time in Los Angeles.

Futaba's initial interactions with Kazuhiro Nakamura are marked by frustration, struggling to decipher Kazuhiro's metaphorical language and resenting being paired with him. Gradually, Futaba learns to interpret Kazuhiro's unique communication, forging a closer bond. This newfound understanding culminates during a pillow fight, where Futaba notices Kazuhiro and assists in sealing him inside a sleeping bag, showcasing their improved rapport.

Choosing authenticity, Futaba stops concealing his passions. He openly shares his interests with Tomoki Takashima, bonding over their mutual enjoyment of the game "iLive!". His surname, Mikuriya, translates to "kitchen," while his given name, Futaba, means "bud/sprout, two flat things".