Squid Girl gets a fever which she believes to be a special squid disease revolving around a craving for shrimp, so Eiko tries to help her stay off shrimp until she gets better. Later, Squid Girl learns about the fins on her hat and everyone tries to figure out what they are used for. She also gets into a debate with one of Takeru's friends over sandcastles, shaming his father's sandcastle with one that could move. Later, Squid Girl becomes fascinated by umbrellas, believing them to be ideal weapons. After entertaining a crowd with a trick, the umbrella gets run over by a passing vehicle, deeply saddening her until Eiko comes and shares her umbrella with Squid Girl.