Cute plot =)
Although some parts are kinda iffy. If you've been unwillingly (is that even a word? xP) injected with heroin then you're gonna NEED to go to a hospital and get pumped or some shit. And if Gee/Mikey did love ickle Frankie then they'd have taken him there. No matter what. I also doubt that people would waste heroin on some little dude sitting in an alley, because heroin is pretty damn pricey.
Also - regarding Mikey + self harm, would Gee really just give him bandages? I mean c'mon! Its a really huge problem that needs medical attention - not just a band aid to fix it.
Other than that I like it =)