Sumire can't catch a break at all
In that world this feels like some kind of NTR play tbh
and what's worse, it's unintentional, Sou is sleeping, so it's just Sumire being Sumire
Wow I actually has very little hope with the protag but this protag actually could got furious and uses the "she almost kill me so I will kill her" as leverage to deflower her sister, and not even hesitate to call her pig when she refuse to give name the first time
IMO He's not really a good...