Ikki and Erika decide to do a report on Medabots and Medafighters for school. Metabee finds a Mermaidl Medal while strolling. The peeps put the medal in to Brass and the find out that this medalwas lost when her Medafighter had to move somewhere else, and forgot her medal. Metabee insists on finding Oceana to her Medafighter Hannah. When they find her, they find out that Oceana's body was lost during the move too. Erika, being the great invstigator she is, located the guy who found Oceana's body, but he refuses to give ot back. Now Metabee has to Ro-Battle Kuraba, a Crab type Medabot, to win her body back.
夏休みの宿題の自由研究で、メダロッターの生態を研究しようと、アリカに誘われたイッキは、カリンちゃんもメダロッターだと言って、カリンちゃんの家へ行こうと提案する。行く途中、メタビーがマーメイドメダルを拾った。
Ikki y Erika encuentran una medalla e intentan devolvérsela a su dueña.