Kiokusoushitsu no Ore Niwa, Sannin Kanojyo ga Irurashii

A strong blow to the head. This is my first memory. The reason why this is my first memory is because I have no memories before that. I woke up in a hospital room, and as visitors came to visit me. I realized something: I have three girlfriends! Each of my three girlfriends is unique and attractive in her own way. Asuka Minato, is a childhood friend who takes care of my house. Saki Arisugawa is a charismatic model in the same class. And Hina Fueino is a cute little otaku junior girl. I have three girlfriends, yet I have no memory of them, and my school life begins in a state of unbelievable anxiety! What in the world did I do to get into this...! (Source: MF Bunko, translated)