Taiga Hirano is a high school student serving on the disciplinary committee, recognizable by his piercings within the school setting. His narrative deepens significantly in the spin-off "Hirano and Kagiura," where he becomes roommates with first-year student Akira Kagiura. As Kagiura's senior, Hirano nurtures his well-being and eases his transition into dormitory life, establishing a foundation for their evolving dynamic.

During their six-month period as roommates, Kagiura develops romantic feelings for Hirano, who remains unaware of this emotional shift. The spin-off chronicles their interactions, focusing on Kagiura's growing resolve to confess his feelings before their shared living arrangement ends. Hirano's involvement in the main storyline intersects with the broader friend group, including Sasaki and Miyano, particularly during events like exam preparations and graduation.