But Sengoku's already in a triangle with Rion and the class rep. It's more like Kitomi had to die in order to make room for her other two friends to get together. Either way, this is just about the first time in Cage of Eden that someone dies who's had more than two lines of dialogue, isn't it? You have to kill off named people from time to time to maintain the sense of danger
Though if someone like Rion were to die, Sengoku would snap, and the group would fall apart quickly after that.
About the scars, they might say it's cool in the manga, but there's no way those scars would actually look cool in real life, no matter how much of a pretty boy he was originally