Cue Chapter 37...
ML:"We found out the truth"
The father b***slaps the crap out of the sister
Then the sister gets even more mad and wants to kill the FL.
(this isn't what happens but I can definitely see the next chapter like this.)
This story turned into "I'm terminally ill but my brother is a reincarnated god of medicine"
(I still love this story and hope that we get another season for the anime too.)