The series (translated as The Summer a Boy Became an Adult ) follows the story of Ryuuki Kirishima , a young football prodigy who has been living alone since his parents passed away and his older sister, Reiko , moved to Tokyo for her chemical engineering career .
: Ryuuki’s protective older sister and a chemical genius who has raised him since their parents' death. -NekoPoi--Shounen-ga-Otona-ni-Natta-Natsu---01-...