Everything (and nothing, all in one)

Takashi Shirogane lives in a castle of glass, wood, metal, and concrete in an unsuspecting suburb of Southern California.
He hasn't been outside in eighteen years.
If he did, he would die. There's no arguing that fact.
He doesn't even want to die, not until someone moves in next door that makes him want to change everything.

(A shance AU, based on the book and film Everything, Everything by Nicola Yoon)