Frustrated by Yukari's constant riddles and insincerity, Reimu decides to actively confront her relationship with the youkai, and with Gensokyo itself.

It's a fact that super-unified physics student Usami Renko can no longer ignore: she's in love with her best friend, Maribel Hearn. When their two vastly different worlds, the worlds of reality and fantasy, of subjectivity and objectivity, come crashing together, will their friendship become something more, or will everything prove to be just an empty dream?

Reimu's holiday plans are interrupted when she comes down with a nasty illness. A short little Christmas story. (Note: ReimuxYukari shipping. Avoid if that's not your thing.)