Haruka is the younger sister of Nanami, they are not really sisters because Nanami mom and dad found her an the bench and kept her and treat her as their own child. When Nanami and Haruka have no place to go because of their dad they go to the park and they meet Mikage and then they told to Mikage that they have no place to go Mikage decide that he will give his home to the two homeless girls. And then they meet Tomoe.............................. You will find out the next part when you read this:-) So read if you want to find out:-)