In this episode, everything revolves around Miri's class preparing for the Christmas party by learning the song "Silent Night." Meanwhile, Kazuki and Rei struggle with the decision of what to give Miri for Christmas. The episode takes an unexpected turn when Misaki, Miri's birth mother, suddenly appears and wants to take Miri back.

Misaki justifies her desire to reclaim Miri by citing her difficult life situation: she has lost her job and her partner and must confront the progression of her cancer. As a result, she seeks a new chance to be with Miri, prompting Kazuki and Rei to reflect on their own roles as caregivers. When it becomes clear that their profession as assassins puts Miri in danger, the situation grows even more complicated.

Throughout the episode, the significance of the relationships between the characters takes center stage, emphasizing the bond between Kazuki, Rei, and Miri. On their last day together, the trio engages in various activities and enjoys their time as a family. This culminates in the heart-wrenching scene of handing Miri over to Misaki.

Despite the series' typical lack of action, this episode is one of the strongest so far. The emotional stakes are high, and the character-driven narrative highlights the impact of their shared journey. Viewers are deeply immersed in the fate of Kazuki, Rei, and Miri's unconventional family, a testament to the strength of well-crafted storytelling and character development.