Muginami transfers into Madoka's class, which causes worry for the organisation. Later, Youko and one of the organization's representatives talk to Madoka's teacher about her piloting Midori. Youko agrees to let Madoka continue piloting Midori on the condition that she is allowed to continue living at home and attending school. Soon afterwards, Madoka and Muginami participate in an open swimming contest whilst Lan keeps watch on a boat. Spotting her, Muginami decides to play a prank on Lan and tip her into the sea, unaware that she is unable to swim. Realising her mistake, Muginami helps Madoka rescue Lan and performs CPR on her. Afterwards, Madoka invites Muginami to join the Jersey Club, much to Lan's annoyance. Both Muginami and Lan decide to help out at Madoka's family restaurant, with their individual traits attracting many customers. After becoming jealous after Madoka allows Muginami to live with her, Lan also decides to transfer into Madoka's class, join the Jersey Club and start living with Madoka. Meanwhile, a glitch in security allows Array to escape imprisonment and rejoin his allies, who are making a deal with another enemy.
まどかのクラスに、ピンクの髪のふわふわ少女、ムギナミが転入してきた。以前ファロスの格納庫に潜入していたムギナミからまどかを守るため、ランは独自にムギナミの監視を始める。
一方、ファロスの田所司令は鴨川女子高校に出向き、担任のまちこらを交えて、まどかに引き続きウォクスの操縦を任せるかどうか、話し合いがもたれた。従姉妹のようこの「ジャージ部、宇宙デビュー」という言葉に背中を押されるまどか。
翌日は、鴨女恒例の遠泳大会。思わぬトラブルに巻き込まれたまどかを助けたのはムギナミだった。抜群のプロポーションを見せつけるだけでなく、まどかに迫る勢いの水泳技術で人命救助までやってのけるムギナミ。感心したまどかは「あなたみたいな人を待ってたの！」とジャージ部に勧誘する。ジャージ部入部を快諾するムギナミとまどかの距離は急接近！置き去りにされ、思わずライバル心をむき出しにしたランのとった行動とは…。
