Kaori Yuki

"Setsuna has seven days to find his beloved sister Sara in the afterlife, and the first stop is to find the Guardian of the Hellgate -- a being any normal person would avoid! Kato, an old enemy of Setsuna's, is now his only companion, but Kato has a history of being manipulated in life. Now that he's dead at the hands of Setsuna himself, just how far can he be trusted?" -- p. [4] of Cover.

Why is Setsuna so mixed up? Despite his attempts to be noble, he'll fight anyone anytime; he ignores all authority; and he harbors feelings for his sister that can only be describes as "incestuous." Why is he such a mess? The reason may be found with two demons from the underworld and their enemy, an insane angel who is distributing an insidious computer game call Angel Sanctuary.

At the center of this epic tale of Heaven and Hell and forbidden love is high-school student Setsuna Mudo. He's no angel - he's completely tactless around girls, has an unpredictable temper, and can become extremely violent. That he comes from a broken home and is in love with his sister Sara just makes matters worse. Add teenage hormones and major issues with his mother, and you've got the recipe for one troubled kid. And then Setuna's reality becomes...