Tomoaki Yamagishi, a young faculty member at the school hosting the Literature Club, assumes the role of club advisor after student Hitoha Hongō blackmails him with knowledge of his anonymous online identity, “Milo,” from an adult chatroom where the two previously interacted. His initial hesitation to engage with the club stems from Hitoha’s persistent efforts to transform their clandestine digital connection into real-world influence, complicating their dynamic.

Physically, he sports short black hair, glasses, and striking lilac eyes. Professionally, he strives to guide club members while cautiously navigating ethical boundaries. His mentorship of Hitoha involves unorthodox methods to enhance her writing—such as awkwardly suggesting she discreetly reveal her underwear or wear specific undergarments—rationalizing these actions as practical inspiration despite their clear lack of professionalism.

When Hitoha propositions him physically, he reluctantly agrees to meet at a love hotel but ultimately withdraws, conflicted by personal reservations despite mutual attraction. This pivotal moment underscores his struggle between duty and vulnerability. Later, he provides reflective, mature counsel during a critical crisis, aiding protagonists in navigating their interpersonal conflicts.

The series concludes with his unresolved dynamic with Hitoha, though an epilogue reveals his eventual marriage to colleague Tomita, signaling a turn toward stability. His journey navigates mentorship, blurred boundaries, and the tension between personal ethics and external pressures, balancing intellectual curiosity with cautious restraint. Throughout, he remains a stabilizing force amid the students’ emotional turbulence.