Waka overhears Seo talking with Kashima and Chiyo about their plans for the summer beach trip he's just been invited to, and his misapprehension only grows as he misinterprets their casual discussion. Worried about their planned swimsuit buying trip, he shows up at the mall and gets roped into their outing. Assuming Kashima is another guy roped in, his behavior becomes more and more… questionable. (thetvdb.com)