As Mayuri Shiina prepares for a Christmas party for everyone at the lab, Rintaro shows Amadeus Kurisu – whom he keeps a secret from his friends – around Akihabara and the lab. On Christmas Eve, Leskinen and Maho end up joining Rintaro at the party, which proves to be more than a surprise when Suzuha assumes it is an ambush and almost attacks Yuki. While everyone else enjoys the party, Mayuri overhears Rintaro speaking happily with Amadeus Kurisu, prompting Maho to step in and remind him that the real Kurisu is still dead, at which point Rintaro feels a strange sensation.