During their first night sharing a room, Yuzu had her first kiss stolen by her step sister. Since then she can't get Mei off her mind, while Mei herself goes on as if nothing happened. Meanwhile, Mei's Grandfather, the chairman of Aihara Academy, takes Mei back to his mansion. Unable to forget the sad expression on Mei's face when they kissed, Yuzu heads to the mansion to confirm Mei's true feelings, but...?!

With her dislike of Yuzu and Mei's relationship, Matsuri uses the secret photo she took at the shopping mall to blackmail Mei into fooling around with text-pal on Christmas. Meanwhile, Yuzu knows nothing of this and struggles to bake a cake for her first Christmas together with Mei. While her excitement builds, Mei comes home and breaks the news that she won't be able to join their Christmas Party due to student council work...

Yuzu promises Nina that she'll support Sara's love with her, but after learning that the girl of Sara's destiny is Mei, she can't help but feel shaken. Nina ignores all the attention she's drawing, desperately holding Yuzu back to keep her from going to Mei. During their conflict Yuzu gets a call from Sara on her smartphone, saying "There's something I need to give you." She quickly races to the overlook, but Mei isn't there, only Sara greeting her with a slightly sad smile as she returns the student ID Yuzu dropped earlier.