As a high school student, Shinji Nagumo had a problem. His adopted-sister, Tsumugi, who came for family reasons, was unfriendly. Living with two people who couldn’t shorten the distance. One day, the “net friend” brought by Tsumugi changes the situation. It was a popular girl gal- Takarai Yua!? From the same class. As the three of them spend time together, Tsumugi became more open minded. In addition, the distance between him and Yua was also close at home !? Only he knows the kind Yua, her lonely face, and her homely side that he was not good at. “I’m like Nagumo-kun’s wife. Is that okay?” “That’s okay! Shin-nii, let’s live with three people!” No, that’s no good… Go home together and stay together. Tsumugi misunderstood Yua as his lover, and for some reason she seemed to be happy. Every time she comes into their house, their relationship gradually becomes real!? Gal and step-sister. A warm and sweet romantic comedy with two girls!