I don’t need any deep relationships. I have no desire for a girlfriend, and I only require one friend who holds any value to me. Ever since I threw out my youth for the sake of efficiency, there is one person who keeps entering the bedroom of Ooboshi Akiteru. She’s neither my little sister nor my friend. She’s nothing more than a bothersome, annoying Kouhai, as well as my friend’s little sister: Kohinata Iroha.