Hokuto "Toto" Mitarai co-founded the Don Glees club with Roma Kamogawa in childhood, stemming from their mutual avoidance of social interactions—the club's name "Don't glee" reflecting their refusal to smile or play with others. At 15, he moved to Tokyo for high school but returned to his rural hometown a year later, exposing a widening rift between his urban academic life and his past.

During this visit, Toto wrestled with Roma's deepening bond with their new friend Shizuku "Drop" Sakuma, viewing Drop as a threat to his longstanding friendship with Roma. His academic pressures dominated him, evident when he carried a cram school textbook on their urgent hike to retrieve a lost drone, planning to study for an exam mid-mission. He consistently resisted activities he deemed childish, mirroring his inner conflict between his father's expectation to become a doctor and his own undefined aspirations.

A turning point came when Toto burned his textbook in a campfire, symbolically rejecting his father's imposed path and admitting his reluctance toward medicine. This act coincided with his confession of uncertainty about his future, starkly contrasting his prior academic focus. After Drop's death, Toto joined Roma in traveling to Iceland to fulfill Drop's final wish. There, they discovered Drop had orchestrated their initial phone contact, which deepened Toto's grasp of friendship and legacy. The journey enabled his emotional reconciliation with Roma and acceptance of his evolving identity beyond parental demands.