When Keroro is hospitalized with a bad back, Kululu becomes acting commander in his place, a terrifying prospect for the rest of the platoon when they have to show hospitality to a peevish but important ambassador from another planet. Later, right when ninja Koyuki wants to become "normal," the Keroro platoon invites her to join their new "Let`s Become Normal" class, but little does she suspect it`s really their secret plan to turn her into a Pekoponian spy!