Again; once more — used to complain or express frustration that something has happened repeatedly.
彼はまたしても遅刻した。
He was late yet again.
またしても雨で花火大会が中止になった。
Once again the fireworks festival was canceled because of rain.
同じミスをまたしても繰り返して、上司に叱られた。
He repeated the same mistake yet again and was scolded by his boss.