Chris Brown & Karrueche Tran Living Together Again!

Call her crazy...But Karrueche Tran and Chris Brown are full-on living together.

They hooked up days before his 24th birthday earlier this month and she's been staying at Chris' Hollywood Hills home ever since.

Though she's keeping her own apartment -- smart -- she's already moved most of her clothes and other personal belongings to his pad.

And it's not like they've been secretive...