If her sister is the strongest heroine, it can't be helped that things like this happen.

ヌき処「にくまる」 - If her sister is the strongest heroine, it can't be helped that things like this happen.

彼女の妹が最強ヒロインならこうなるのも仕方ないか。 If her sister is the strongest heroine, it can't be helped that things like this happen.