「しまったぁ……虫除け持って来るの忘っすれたぁ……！」

鍛錬（キャンプ）に来たものの、色々と迂闊な彩羽さん。

https://fantia.jp/posts/2144596

"Oh crap... I forgot to bring insect repellant......!"

This is something that came up whilst training her discipline (camping) with the careless Ayane-san.

https://fantia.jp/posts/2144596