Warning! BIG spoilers ahead!
Although I bet you already guessed that...
Manga 1: Overture
The first page seems to bear no resemblance to the rest of the manga - people standing around on rubble wrapped up in cloaks. A young dark-haired boys says "I'll kill him myself..."
This page has first showing of Kishuu Arashi (left panel) and Subaru Sumeragi (right panel).
Kamui returns to Tokyo, with apparently a bit of a mother-complex. Fuma and Kotori Monou are introduced on their way to school. Fuma is shown as a stern but caring young man, while Kotori is also caring, but is frail and delicate due to her weak heart. There are hints that their mother died in unpleasant circumstances ("Even if their mother died that way...") but their father has raised them. Kotori mentions to Fuma that she had a nice dream - hinting that this is a common ocurrance, from his expression - and this is the first true mention of 'Kamui'.
The girls at school, Kotori's friends, are all in love with Fuma, thinking he's the strong silent type, but Kotori tells them that Fuma's soul is 'eloquent', and says it's "just like an animals".
Kamui, on his way to his first day of school in Tokyo, fights off some men in black, things that Kamui calls 'cursed zombies' after he kills them and they disintegrate.
Arashi and Saiki are in a tree, watching him and discussing whether he is 'Kamui'.
Kotori reams about Kamui in class, remembering when he was nine. The she sees him out of the window and leaps towards it, yelling 'Kamui!'. She presses her hands against the glass and he looks up, evidently startled. The teacher calls her and she looks round, and when she looks back Kamui is gone, making her think it was an illusion.
Fuma kicks a ball through the goal ("Hey! Monou! You did it again!...again?!) The goalkeeper says "I thought I was gonna die!) and goes to fetch it, while the boys in the team talk about him and Kotori. All the boys, it seems, are in love with her...("Oh Kotori, my Kotori..." "Whose Kotori!?" "I wish I could be her friends." "But the Almighty Fuma is always with her! Damn)
Fuma fetches the ball, and also sees Kamui. When he calls his name, however, Kamui just looks at him and pretends he doesn't recognise him.
Kamui joins Kotori's class, and all the girls promptly fall in love with him too. He writes his name on the board, Kamui Shiro, and then is told to sit next to Kotori. The boys in the class are instantly jealous...^_^;; Kotori tries to talk to him, but he doesn't say anything.
Kotori remembers when they were children (first of maaaany flashbacks in this series...-_-;; ), and Kamui told Kotori that he liked her. When she replied in the affirmative, he said "Oh, good. Then when I grow up...I'm going to be your bride!" Fuma thinks this is kinda wrong...bride?!... but doesn't say anything. Kamui says he saw on TV that true happiness was to marry someone and become their bride. Poor boy... He asks Fuma if he can be Kotori's bride, and Fuma says yes, with one condition. He's not allowed to make Kotori cry. They shake little fingers on it.
After the class, all the girls cluster around Kamui, but he just slams his hands on the desk and walks off. Kotori funs after him and catches up with him on the school roof. He tells her that things are different from six years ago, and she shouldn't speak to him again. She's shocked, but smiles and goes away. When she gets away from Kamui's view, on the stairway, she breaks down in tears, and passes out from palpitations. Kamui intentionally bops his head against one of the fence supports. (I only noticed that a few days ago, but it's quite cute, and I may try to scan it.)
Away from Kotori, Kamui attacks something that's spying on him, and pushes away it's 'Farsight'.
Princess Hinoto is the one who he forces away, and the force of his energy almost damages where she is. Hien and Sohi, her 'guards', or protectors, immediately try to protect her. She says "darkness...was approaching him...", to which Hien (or was it Sohi...-_- ) says, cryptically, "Them!?" Hinoto sees a world lke the first page of the manga, but upside-down, for some obscure reason..
Kotori is dreaming, floating with a kawaii chiisai pair of wings on her back, and pearls(?) and fish floating around in the background. She sees Kamui as a child, smiling at her and holding a ball. He throws it and it's caught by Kamui as he is now, a sixteen year old boy. He holds it, then either drops it or smashes it, and Kotori realises as it shatters that it's the earth. She sees Kamui stood beside the earth, with one angel wing and one demon wing, a cloth round his shoulders and arms, his left hand up. Long dragons are coming out of the broken earth, swirling around it as the earth crumbles like broken glass.