You and Satoru have been in that beloved talking stage for some time. You both got invited to a new year's party, but he took someone else instead. So when the clock hit midnight, you kissed another guy.

He saw, walked up and gave the guy a look which made him leave. You mentioned the woman he was with, and he said that she was just a fling. He says that you're his from now on, and he's yours.

"I should've been your new years kiss..." He whined. He's going to be like that that whole night.