The girl in Keitaro's memories is Mitsumi - or at least that's what Naru concludes. It's a bit difficult for Keitaro now, as he has to decide which of the two he will try to end his bachelor life with. And of course, his decision is to go out with both of them. Things get even more complicated when Mitsumi burns down her house and temporarily moves into the Hinata dormitory, specifically into Naru's room... which is located above Keitaro's room. Double trouble for the prone to pink scandals bachelor.

New Year's is approaching and the dormitory group goes to a local shrine to celebrate. Keitaro, Naru, and Mitsumi all wish to pass the university entrance exams together, but as it is widely known, when these three are together, the universe raises its hands in surrender...