It's about a guy who was bullied by his family for being born together with his twin sister. Then when he was in his twenties he was killed by his family after acquiring his company then he went back to being a high schooler which he also gained a knowledge that he was just a cannon fodder. At school he was always bullied because of this so called twin sister.There was also a thing about the sister feeding him food that he is allergic then he questioned the so called "twin sister", why she fes him that, then that caused an uproar where almost every one at school would bully him. then a guy helped him because he saw it on cctv. This guy was bound to be crippled. He was a character too. So the MC targeted him to raise sympathy. that's all I remembered I didn't get to finish it because my godd*m phone was stolen.
Is it BL? Cus if so I've read this before. The MC finds out that hes actually in a novel and his sister is the protagonist? I'll brb ima search for the title real quick. https://www.novelupdates.com/series/rebirth-of-a-cannon-fodder-from-a-novel/ Found it. This should be the novel.