Koujitsusei no Tobira向日性のとびら ; Le Syndrome du tournesol (French) ; 向阳大门 (Chinese)

Cys Beckett learns of the sudden death of his brother he didn't see for 10 years. His only legacy: a disk and a son, Kai. Kai now lives with Sis and every night, comes to his bed. Sequel: Jin to Neko wa Yobu to Konai