Our first yojijyukugo was from Takayasu’s Ozeki promotion. Going backwards chronologically, the previous promotion was Kisenosato and he used the idiom futou fukutsu (不撓不屈). This means “unyielding, unbending.” 不 (fu-)is a fairly common kanji, used to negate what follows it. So this saying is fairly straight-forward. Literally, Not deflected, not bent. This was also the idiom used by the great Takanohana when he was promoted to Ozeki.