One day in the Yamaguchi family's bathroom, in a roll of toilet paper, appears a mysterious (and tiny) girl named Shin - for friends Shini - who at first glance makes a stunning impression on Nobuo, a simple middle school student.
"And if I used all the paper," thought Nobuo, and a drop of sweat rolled down his temple - "Would I see her then ... na ... naked ?!"
And so it begins, a wonderful story of love, lust and ... much more!