Hmm.. let's see. Well spoilers ahead, just to warn you anyone else who reads this ^^
Anyway so the main character (gosh I've forgotten her name 0_0 I want to say Su Ha but that's the main character from Operation Liberate Men XD) she's the reincarnation of the angel of light (the first chapter says so I believe) anyway seems the angel of light was maybe in a relationship with the Lucifer guy, it seems but i'm not sure, they kiss once don't know why 0_o
The evil angel that attacks her in the first chapter becomes her friend later on, when he/she realises Gabriel is her new guardian angel. There's a whole volume where that angel and Gabriel are chibis and hanging out in her room then the now not evil angel becomes human for a while, for comedic effect with everyone wondering if they are male/female and he/she flashing people many times XD.
Oh yeah turns out Gabriel and the Lucifer guy had a big battle and it ended up badly on Gabriel's side as I can guess, as he seems pretty down about it.
Then the main character get's kidnapped by a guy with short black hair who makes her wear a white dress for some reason. Then it turns out he was this guy in ancient China who Lucifer turned into an angel (or what I guess) and then took revenge on the people who massacred his village or something.
There's this whole side story with a child and a female angel (with like breasts XD) which I don't understand at all, seems the child was saved by an angel sometime but I don't know why.
The ending is a bit strange, it doesn't seem to end. There's a black haired woman who attacks the main character as well as some other angel. There's a bunch of new characters introduced in the last chapter and then I have no idea what happens next. Maybe it goes on longer than six volumes... 0_0
So ya XD