relationships with others
Muraki is Tsuzuki's nemesis, anti-thesis, and foil in the series. He's everything Tsuzuki isn't; apathetic, murderous, blatantly sexual, cold, psychopathic, selfish, and etc. Muraki is responsible for many of the incidents over the course of the series, not to mention Hisoka's rape and murder. Hisoka is the only known case of Muraki raping someone, but one of possibly hundreds of his murder victims. He's an extremely evil, insane, twisted (read: fucked up) bastard. His half-brother Saki killed their parents before heading for him, but a servant of the household shot Saki before he could do anything. Since then, Muraki has been on an insane quest to revive Saki just for the sake of killing him with his own hands. Muraki keeps Saki's head alive in an enormous laboratory, and it's for this purpose that Muraki wants Tsuzuki. Not only does he find Tsuzuki attractive and want to mentally break him (since that's how he expresses love? ack), but Muraki wants to use Tsuzuki's immortal body in order to revive Saki. In the meantime, he's killed countless people to satisfy his bloodlust.
Hisoka is Tsuzuki's partner as a shinigami. Hisoka is very pretty and small for a boy, and a strong empath who grew up in an old, traditional Japanese family. He was expected to be perfect and was pushed and held to impossibly high standards as the heir of the family. Once they found out of his ability to read others' minds and feelings, they locked him in a cell in the basement for most of his life. So he grew up not only without kindness, but he was treated with revulsion and called a monster. At 13, Hisoka was wandering the gardens one night. Under the light of the red moon, he witnessed Muraki killing someone. Muraki, of course, can't have witness...but he deemed Hisoka too beautiful to kill the same way. So Muraki raped Hisoka...while carving a curse into his body. It slowly killed Hisoka over the next three years as a terminal illness that doctors couldn't cure. The curse still appears on Hisoka's body when Muraki is "active", and probably always will until Muraki ceases to exist. So Hisoka has grown hard thanks to his many horrible experiences, but Tsuzuki wormed his way into his consciousness in a way no one else had.
Grell - likes him a lot! Grell kinda reminds him of Watari, except less mad scientist and more Shakespearean homo.
Joshua -
Matt -
Rin -
Tinkerbell - thinks she's adorable! playfully flirts with her.