
Well I agree the most part but I dont feel sympathy for his feelings
He wanna hurt his brother yeah He probably prefer his being alive but He still want him the hurt and wanted sensei attention. He clearly have self esteem issues and He blame his brother for that
His brother didn't even do one single mistake He fall in love and confess his feeling. He didn't deserve this kinda end.

True, this story is extremely unfair to his brother. He did absolutely nothing wrong. He should've gotten his own happy ending somehow. I feel sad for him. And yes Akane clearly had (self-esteem) issues and a lot of them.
But because the brother is dead the story has more depth and to me this story is a bit heavy to read but I love it that way. The story is absolutely great! I can feel all the emotions, sadness, regret, loss, frustration...
Akane knows he killed his brother. HE killed his BROTHER, beloved by everyone, the kind and outgoing brother that everyone adores.
And clearly a day hasn't gone by without him thinking of that. Akane feels like he robbed Mei's life, the happy life he was supposed to have.
Maybe because Akane too had feelings for Keisuke that the first thing he did was comforting/"apologizing" to Keisuke (in the hospital). And since then they supported each other after Mei's death, Keisuke was feeling lonely and Akane felt like he head to be there for Keisuke because it was his fault that lovely Mei was no loner alive. I think Akane thought it was his... retribution? A way to try and make amends with the life itself? Which failed since he constantly thought how he wasn't enough and how it should've been him who died.
And maybe that's why things culminated to Akane pretending to be Mei. He perhaps wanted to erase his life-altering mistake and let Keisuke feel the happiness he was supposed to have. But it is impossible to became someone who you're not.
I don't really want to blame Akane for Mei's death. IT WAS A COMPLETE FREAK ACCIDENT. He was angry, felt frustrated since Mei, who supposedly had everything that Akane didn't have, said not to take Keisuke away even though Mei and Keisuke were already dating, while Akane only had one-sided feelings towards Keisuke. That pushed Akane over the edge and he lashed out on Mei and pushed him. I'm sure he had no idea that there was a truck speeding towards them. I'm sure he didn't mean to hurt Mei. It wasn't supposed to happen. But it doesn't change the fact that Akane's actions caused the death of his brother. He is guilty.
And in my eyes, he repents.