college byler but they end up on decently far away from each other and mike is too scared to call will and will thinks that mike doesn't want to talk to him so they drift further and further apart until one day holly, who's still at the wheeler house in hawkins, finds a box in mike's closet while poking around to find some of his old dnd stuff that is packed to the brim with letters to will that mike wrote while the byers were in california, and being the lovely little sister that she is, she sends them, getting will's address from joyce under the guise of mike needing it for some reason.
will, upon receiving the first letter, calls mike immediately because he thought that mike was purposely ignoring him why was he suddenly sending him old letters saying that he loved him???
mike, who had no idea holly found said letters, is panicking and thinking oh fuck he definitely hates me now if he didn't before and hangs up the second he figures out what's going on.
will then calls jonathan bc like wtf just happened, who convinces him that mike does not in fact not want to talk to him and is probably just repressed as hell because of the way the wheeler household is built, supported by nancy in the background telling will "please go knock some sense into him mike's too scared of his feelings to register that you probably called because you like him back"
then ensues a chaotic trip from will's house to mike, where he stops at multiple friend's houses along the way, gathering advice and support until he finally makes it to mike, who has been hiding from the outside world since getting will's call and realizing that the letters that he thought no one would ever read were out in the world, and they talk. and kiss. and kiss some more.
