This episode is all about Miri's class preparing for the Christmas party by learning the song "Silent Night". Meanwhile, Kazuki and Rei struggle with deciding what to get Miri for Christmas. The episode takes an unexpected turn when Misaki, Miri's birth mother, suddenly shows up and wants to bring Miri back.
Misaki explains her desire for Miri's return with her difficult life situation: she has lost her job and her partner and has to deal with the progression of her cancer. As such, she searches for another chance to be with Miri, leading Kazuki and Rei to confront their own role as carers. The situation gets even more complicated when it turns out that her job as an assassin puts Miri in danger.
Throughout the episode, the importance of the relationships between the characters takes center stage, underscoring the importance of the connection between Kazuki, Rei, and Miri. On their last day together, the trio engage in various activities and enjoy time as a family. This culminates in the heartbreaking scene of Miri handing over to Misaki.
Despite the lack of action typical of the series, this episode is one of the strongest yet. The emotional stakes are high and the characters' storytelling reflects the impact of their journey together. Viewers are deeply immersed in the fates of Kazuki, Rei and Miri's bohemian family, showing the power of well-crafted story and character development.