From Tokyopop:

Kyoichi Utsume, a.k.a. "His Majesty, Lord of Darkness," is a dark and compelling mystery –- so much so that his fellow Literature Club members would rather discuss him than books! When "His Majesty" vanishes in front of their very eyes, his friends are left with several unanswered questions: what is the source of Kyoichi's long-standing obsession with the "other side"? And just who is Ayame –- the eerily ghostlike girl Kyoichi brought to school as his girlfriend the day before he disappeared?