Reincarnated as a bedridden side-character

Tooru Fumiya was just taking in the news that his parents were getting a divorce, with his mind spinning around as he tried to go to a place to calm down. However he would never get there, as he was run over by a speeding car and wasn't being able to react quick enough to it.

But he woke up, to his own surprise, in a completely foreign room. A letter sitting on the cabinet beside the bed...
With hands, hair and a body that isn't his, how will he be able to survive in this new world?
Even worse, he's deathly sick!?