He is Kotori Monou's elder brother. He is the leader of the Seven Angels. He also holds the destiny of the future like Kamui does. He is the person to fill up the space after Kamui choose to be a Seal or an Angel. If Kamui choose to become a Seal, Fuuma himself will become as Angel.

His appearance is changing, he looks like a mirror image of everybody as times goes by. (Fuuma sometimes looks like Kamui) (Subaru feels that Fuuma looks like Seishirou) (Yuzuriha feels that Fuuma looks like Kusanagi) (Nataku feels that Fuuma looks like his/her father)...

His goal is still unknown!

He is very very kind. He has almost the same power of seeing the future in the dreams as Hinoto has. Since every dreamgazer must give up something, he has given up his ability of dying. All the people he love have died, but he can't kill himself. Becoming one of the Seven Angels is the only way to finish his life. He once saved Kotori.

He always says that he has lost his only love, but he doesn't tell who she is. In X-14, the last page finally talks about his only love and she is also one of the main character from "Tokyo Babylon" [another great story produced by Clamp] called, Hokuto. Hokuto is the elder sister of Subaru. He saw Hokuto's death in his dream & he rushed out of the house trying to save her but he got shot by the guards (those guards were trying to stop Kakyou from leaving the place that Kakyou is living). That's when he lost his ability to go anywhere.

Nataku is an artificial organism and has no soul nor emotional changes. Nataku's father (Masaki) and Nataku's grandpa (Toujyou) spent a very long time to "invent" Nataku. [Since Nataku has non gender, I just have to repeat his/her name again & again.] Actually, there was a little story behind Nataku. Nataku was a little cute girl called Kazuki. Masaki & Toujyou loved Kazuki very much, but Kazuki got a very bad disease & died when she was still a child. Masaki promised Kazuki that he will bring her back alive again. So, Masaki & Toujyou started their project of making Kazuki alive again.  Since Kazuki's disease has destroyed most parts of her body, Masaki gave his body to Kazuki in order to complete this project. [that means Nataku has some organs of Kazuki & the body of Masaki] Although Nataku has changed into a whole new person, Nataku still have a little part of Kazuki's memories in Nataku's mind.

He finds that Fuuma & his father looks very alike, that's why he stays by Fuuma's side and become one of the Angels.

He is one of the main character in "Tokyo Babylon". [another great story produced by Clamp]

He is a cold-blooded killer. He will never feel sad or sorry of what he did, even killing his own mother. He killed Subaru's elder twin sister called Hokuto. He tortured  Subaru almost to death for a few times in Tokyo Babylon. [ So sad! >_< ]

The fight between Subaru & Seishirou continues in this story...

She is the lover of the computer called "The Beast". "The Beast" is the one of the most high-tech. computer in the world. "The Beast" will tell her everything & that's how the Seven Angels got the information they need. She loves Yuuto. (she only likes the computer)

She killed Yuzuriha's dog in a battle.

In the anime, Satsuki got killed by the computer when she called the computer to save Yuuto. [of course, the computer would never save Yuuto] The computer feels very jealous and it doesn't let anyone to have Satsuki, so the computer killed Satsuki in order to own her forever.

He loves Satsuki Yatouji. He works in a government department. The computer hates him very much because Satsuki loves him. [Computer also knows how to jealous!]

He has the ability to listen and understand the feelings of all animals and plants. He is in the army. In the manga, he treats Yuzuriha very nicely & he cares about her. He even dated Yuzuriha because he doesn't know that Yuzuriha is a Seal at that time. He even saved Yuzuriha after he knew she is a Seal. 

(He only appears in the anime because there is no Kakyou in the anime.)

His background ... unknown ...

His weapon is quite special. He killed Yuzuriha in the anime. [So cruel!]