Tōsei Aoe, the head of a newspaper company employing the protagonist, harbors a deep-seated aversion to women rooted in childhood abandonment by his mother. This resentment fuels his dismissive treatment of female staff, though the protagonist’s defiance of societal norms challenges his biases, earning her an uneasy exception. When the Ijuin family faces financial ruin, he intervenes to prevent their estate’s repossession and proposes marriage to the protagonist following her broken engagement, framing the union as a pragmatic safeguard for her family’s future. During the 1923 Great Kantō earthquake, his conflicted loyalties surface as he attempts to extract the protagonist from danger, only to find her refusing to abandon her injured former fiancé. Despite her rejection, he ultimately rescues both.

Post-disaster, Tōsei confronts his lingering trauma over maternal abandonment, channeling his energy into business endeavors. His bond with the protagonist remains strictly platonic, devoid of romantic fulfillment. A secondary narrative explores unreciprocated affection from a female colleague aiding his company’s operations, underscoring his emotional detachment. Earlier adaptations condensed his arc, excising later manga developments, but the 2017–2018 films fully depict his financial maneuverings, marriage proposal, and seismic reckoning with his past.