The Arakawa residents decide to do a physical checkup to prepare for their trip to Venus, and Kou and Hoshi end up trying to 'outsick' each other to get Nino's attention. Later, the girls spend a week in Sister's basement, though after six days everyone drops out except Nino. When it's the boys turn, Kou tries using P-ko's logbook to strike up a conversation, with embarrassing results.