Yui has the Christmas spirit and Ayato...well, maybe not so much.

"Damn human, don't ask me why! You're supposed to be the one explaining it to me. This... This mundane feeling. I'd rather go kill myself than admit it. Or rather, I'll probably just kill you so it would go away." He does what he does best- being a jerk. That is why Yui is perplexed on how Ayato is becoming more and more, well... in love with her? Read how their story unfold.