While still on vacation, Grandma Hina calls to inform Haruka of Keitaro’s “treasured items” being hidden in the Annex, however, Mitsune intercepts the call and mishears the message. Thinking that there is treasure hidden in the apartments and that Keitaro knows where it is (or at least has the treasure map on his person) the Hinata girls start making various attempts to see Keitaro naked.