Deaimon: Recipe for Happiness

One day, with Christmas near, a message and a fir tree sent by Itsuka's mother arrive. Remembering back to the broken promises from when she was little, Itsuka is afraid to make another promise with her mother. But Nagomu's words give her a push, and she tells her mother that she'll be waiting. Yuzu yokan causes Nagomu to remember a conversation he had with his grandfather.