Hello, I am the only man and I live along with my five Nino sisters, Miku, Yotsuba, Ituki, Ichika the five are in love with me for a promise that I made years ago which would be that it would be that I would marry me and they were happy with my decision but when I grow up I realized what I can not marry my sisters losing hope and forgetting the promise while they do not forget them and forget the promise. Promise, now they will do their best to fulfill that promise.