@Tahaku I think she's talking about demons. Her colleague was killed. Even though she intends to carry out her sister's desire to befriend them and stuff, instances like this when a person she knows gets killed by them makes her furious against them again.
@Tahaku@MianneChan no I'm pretty sure she's talking about men, like "men are all the same" or something, specifically referring to Tanjirou sneaking out instead of resting
Rengoku deserves better plot instead of just being used as a motivational source of character. For me, he died unnecessarily just for giving the three of them a spot to become a hashira when the author could just made him crippled or out-of-combat state instead of being a drop dead and using him at the cover page etc. I could picture him giving a stern hashira's training for the three of them, but he was dead instead. Well its up to the author and its only my own opinion. Rengoku was the only hashira that caught my eyes with his vibe and i felt bad for him being like this. Live on rengoku.