Yüko suggests throwing a surprise birthday party for Nano, which Mai and Mio agree with. In the Shinonome Laboratory, the Professor has made a smaller wind-up key for Nano, only for Sakamoto to accidentally crush it. The Professor promises to have a new one ready before Nano gets home from school. At school, the Principal is shocked to see his statue replaced by one of the Vice-Principal, whose plot is exposed when the movers reveal they still have the Principal's statue and dislike the Vice-Principal's statue...