On the cold winter night of Alya's birthday party, Masachika finally reveals to her that Yuki is his little sister. Alya can't stand to watch Masachika beat himself up for abandoning his younger sibling, so she pushes him to visit Yuki, who has fallen ill. Masachika moves forward despite his doubts, and at last, he will confront his mother and grandfather. Meanwhile, Alisa--now fully informed--can truly communicate with Yuki for what feels like the first time. In the Suou household, affection, determination, and love collide!