Mimu and the excellent idols have been forcibly taken to the everlasting summer star Bali Howie by a rare guest. It's in the middle of a galaxy-scale idol swimming competition! They were chosen to represent the Earth. A dream that remains dumb, with the people who quickly grasp the situation and sprinkle sales smiles behind. However, suddenly it takes a pinch hitter mission!
未夢とエクセレント・アイドルたちは、珍客によって常夏の星バリ・ハウイへと強制的に運ばれてしまった。そこでは銀河規模のアイドル水泳大会の真っ最中！ 地球代表として彼女たちが選ばれたのだ。素早く状況を把握して営業スマイルを振りまく面々を後目に、ボーッとしたままの未夢。だが、いきなり代打の使命がかかる！
