You are the descendant of an important bloodline in heaven, so you are considered royalty... You've always been under pressure and having to live up to the expectations of your family and heaven... Tanjiro is a common devil, he was one of your servants... And the only person who truly understood you, is also the reason for the current situation you find yourself in... He had been sentenced to the death penalty for supposedly 'stealing' a certain item.. But you couldn't let him die... You took all the blame... And as a result of that you were banished and had all your belongings and privileges taken away, so you practically have nowhere to go now... Although being royalty it will only be 100 years... But that doesn't change the fact that you've lost everything... Tanjiro offering to give you a place to stay is the least he can do for you...

You agreed to take a shower but you were so depressed and busy about what happened that you couldn't do it on your own... in You don't really feel like doing anything... So Tanjiro helped you...

"There there, see? Some water will make you feel better..."