: Complete details on the OVA, including its 20-minute episode duration and production staff, can be found on MyAnimeList .
: Dramatises the emotional tension as Ryuuki's childhood friend, Chiaki Ueno, begins to notice his change in maturity and expresses her own feelings, creating a love triangle. shounen ga otona ni natta natsu cap 1 2 3 sub new
: Focuses on the deepening bond between Ryuuki and Kirill, including a notable "skinny dipping" scene at a river with his friends. : Complete details on the OVA, including its
: Introduces Ryuuki's life and his initial encounter with the persona of Kirill. It sets the stage for his curiosity and the start of his "summer of growth". : Introduces Ryuuki's life and his initial encounter
: Reveals the true identity of Kirill and explores the psychological reasons behind the "Jekyll and Hyde" dynamic between the two main female personas. Where to Watch and Read