Zero no Sekai de Hana to Odoru

Asahi was left in front of Viscount Irino's home and raised alongside Touri, the viscount's son, as a sibling. Touri, who regarded him as a true brother, held a central place in Asahi’s life. As they grew older, Touri became a handsome and well-regarded young man, maintaining the same warm relationship with Asahi as in childhood. After attending a noble family’s gathering, Touri returns with an aphrodisiac. Asahi is aware of the inappropriateness of his feelings but struggles to resist them.