Senpai to Boku

24th of December, Silent night, senpai and I went out to look for the floating shadow. At that time we were kidnapped by aliens! The clumsy aliens accidentally swapped our brains, consequently "I became senpai and senpai turned into me... "

My new daily school life is in chaos, who can tell me what is going on?

Note: The series won the Silver Prize in the 10th Dengeki Novel Prize.