Shusuke was living happily with his mother, then cluster fuck happened with Shiika parasite abusing and raping Yuri.
Shusuke was happy at first, but being it a closed community rumours spread fast, bullying happend because stupid kids being stupid kids.
Shusuke mom couldn't bare with being called out as pedophile rapist wife, so she gave Shiika to the orphanage.
Since it's closed community, people gone Twitter to reality, things like that happen. Just need rumours.
Shusuke using his appearance tried most dumbest thing possible to raise money so he and mom can move out of the town, bait prostitution to steal money and it backfired, got raped.
Shusuke clearly lost his mind, going deeper into prostitution, jealous of Shiika that she seemingly had better in life. Although didn't he knew about the abusive pedophile father and Yuri taking place instead of Shiika?
Well, not saying anything like that wouldn't happen realistically speaking but... yeah, life ain't peachy and people can become fucked up through that kind of shit Shusuke got through...
Sumire being at the cemetery that fast?
Orphanage is up the hill, Kazuma drove by car in zig-zag down, she took the path straight there through path.
Sumire was talking with Kazuma where Shusuke was going.
We seen Shiika going to the cemetery after pushing Sumire in winter rather quickly, it's very near on foot.
Poor fucked up kid and it's all because that parasite pedophile parent...
Thanks for scanlation!