ヒーローは電話ボックスで変身するものだという知識を得てとりあえず電話ボックスに入ってみたものの、狭くて着替えづらいし外から丸見えだと途中で気付いたマイティセーラー

Knowing it's been said that heros transform in phone booths, for now, Mighty Sailor tried getting in the phone booth. However, it's narrow, so it's hard to get changed, and you can clearly see from the outside. She noticed this part-way through.