15 years ago, Hiyori and Soushi are going to be living together, and they're both super excited about it. They're all like, "Gee, it's awesome that we're going to live together!" But then they realize that they've been secretly watching each other all this time, and now they have to leave each other alone for the first time in their lives. It's a little weird, but then again, we've seen this before, so maybe it isn't so weird after all. Anyway, the two of them head off to find out what's up.