月山 習

Tsukiyama Shuu is the infamous Gourmet (美食家, Bishokuka) ghoul of the 20th ward. He comes from the extremely wealthy and influential Tsukiyama family which his father, Mirumo Tsukiyama was the head of. 

He joined Kaneki's group with the hidden intention of eating Ken Kaneki, obsessed with his scent and taste but eventually came to genuinely care for Kaneki.

Tokyo Ghoul Wikia