What if, when watching the stars outside the window...
What if, when writing in your secret diary at the end if the day...
...A mysterious light suddenly falls from the sky...

Tsuwabuki Masaharu, or Haru as is friends like to call him, is your normal high school student. Now in his second year, his friends push him to speak with his classmates whom he have yet to speak to, but this was still a difficult thing for Haru due to his clumsy nature.

One afternoon, his life met with a 180° during a strange encounter in the hallways of Hoshigaoka School. During that fateful encounter, he accidentally drinks a magical potion which transforms him into a stuffed animal sheep during the night!

Through later events, Haru learns that in order to return to his original self, he needs to collect "star droplets" that fall from the sky. However, being that his innards are now made of cotton, he will need the help of a "special person," little did he know that special person was someone from his class.

Living a double life between his day self and his sheep form "Yuki-chan", page one of his story, her story, and the story of nanatsuiro drops begins.