Watari-kun no xx ga Houkai Sunzen (渡くんの××が崩壊寸前)

The daily life of high school student Naoto Watari revolves around his little sister Suzushiro. As their parents passed away two years prior, the siblings have been passed from one relative to another, resulting in Naoto taking the most responsibility for her. Although things have not been easy for the two, Naoto is now content with living at their aunt's place. This newfound peace is suddenly turned on its head when Satsuki Tachibana enrolls at Naoto's school. The two used to be good friends, but after Satsuki completely destroyed his family's garden, she disappeared from Naoto's life. Despite what happened, Satsuki seems to be making advances toward Naoto now that they have reconnected. Coupled with other people around him that harbor secrets, Naoto's desire for an idyllic life may be at jeopardy.