Summary Saikin, Imouto no Yousu ga Chotto Okashiinda ga.
A cause of a new family is when the mother remarries a divorcé who has a son.
Since her stepfather is moved overseas, her mom follows him there.
Leaving Yuuya alone with Mitsuki during their transfer. Feeling emotionally rejected by her mother, Yuuya feels isolated from her.
Never polite towards him nor even in a position to have a decent conversation with him.
Until one day…