Six months have passed since Rintaro Okabe chose to stay in a world line where Kurisu Makise is dead, discarding his identity as a self-proclaimed mad scientist.

After a chance encounter with Maho where they discover knowing someone in common, Okabe has his first face-to-face with her special AI, Amadeus.

Mayuri Shiina prepares a Christmas party for everyone at the lab. While everyone is enjoying the party, Rintaro experiences a strange sensation.

Rintaro briefly has a vision of a world line where he is caught up in the middle of a war, he realises it was actually his Reading Steiner taking effect.

Their search continues as New Years swiftly approaches, though Ruka's dilemma with a certain guest might make matters worse.

As Kagari and Mayuri form a bond despite not knowing each other, Rintaro asks Moeka to continue searching for whoever else has been looking for Kagari. Later, the gang celebrate New Year's by dressing up as shrine maidens at Luka's shrine.