Sgt. Frog Season 7 Episode 331 Natsumi: One Week Without Getting Angry, Sir! / Keroro: Always Room for an Invasion, Sir?

Keroro hatches a plan to convert Natsumi's anger into energy for the invasion... or is it just an excuse for him to slack off? Then, a misunderstanding over the expression "dessert stomach" leads the platoon to take desperate measures to get their own version of this "secret weapon."