Just to clarify the bullshit that's been spread by random ass, there ain't no NTR in the next chapters. Although they have no blood relations, 2nd Nao never see Satsuki as a woman nor does he has any interest in succeeding the inn. In the latest chapter, 2nd Nao confronted Satsuki before going back to Tokyo again (of course with our MC), telling her that she's been in love with our MC yet still don't want to admit it. And it also hinted there is also another underlying reason why Satsuki went back to Tokyo when she was still a child. However, that much is still yet to be revealed, though few raw readers speculated it was about her real family.