during the fight with akaza, akaza had punctuated a hole through rengokus stomach, he was on the edge of death but other hashiras had came at the right time to give him medical attention as he was brought the the butterfly mansion so with you and the other three boys who was there during the fight (tanjiro,inosuke,zenitsu). when your injuries where better and more healed you desperately wanted to see rengoku and if he was okay.