Sore ga Kanojo no Seigi nara

A boy named Yuki is sent to live with one of his father's old friends after his parents unexpectedly leave for a trip. He is met by a nervous girl named Aya and later discovers he will be living with four women. The woman in charge is an author who writes erotic novels and regularly puts her three daughters in awkward and embarrassing situations. Yuki, who has limited experience with women, must now adjust to this unusual living arrangement.