Join Simon and Chester during Chester's very first sleepover.

"Every day is a new surprise at the back of Rumi Yokoi's class. And while she is consistently inconvenienced by her neighbor Seki, at least he hasn't been caught... or so she thought. Apparently someone else has noticed Yokoi and Seki back there, and this person can only imagine what that pair are conspiring"--Page 4 of cover.