ひゃくにちのせっぽうへひとつ
百日の説法屁一つ
single mistake which ruins all one's hard work; one blunder rendering a long period of effort useless; one fart in a hundred days of sermons
N3Expression
Expression
single mistake which ruins all one's hard work•one blunder rendering a long period of effort useless•one fart in a hundred days of sermons