Shuu Tsukiyama, known as the Gourmet, was a ghoul born into a wealthy and influential lineage. Generations of consanguineous marriage within his family had left him with a genetic vulnerability, destabilizing his RC cells and impairing his control over his kagune. This condition necessitated a highly selective diet to stave off both psychological and physical deterioration. A student of Social Welfare in the Department of Human Sciences at Seinan Gakuin University, he initially presented a polished facade of confidence, intelligence, and friendliness. This masked a cruel, selfish, and eccentric nature. He was drawn to European literature, fashion, and languages, frequently interlacing his speech with French, English, and Italian phrases. As a self-styled noble predator, he held a deep grudge against Rize Kamishiro for insulting his gourmet tastes. He once operated under the alias MM as a member of the Ghoul Restaurant, an organization he later betrayed. His primary fixation became Ken Kaneki, a one-eyed ghoul whose unique scent he found irresistible. Driven by a consuming desire to devour him, Tsukiyama engineered elaborate schemes, including luring Kaneki to the Ghoul Restaurant and kidnapping Kimi Nishino for leverage. After a failed attempt to consume Kaneki left him severely wounded, he later joined Kaneki’s group following the Aogiri Tree arc, though his motives were still viewed with suspicion. The Raid on Anteiku and Kaneki’s apparent death triggered a profound shift. Tsukiyama plunged into a deep depression, starving himself and engaging in self-cannibalism until he became emaciated and bedridden. His mental state crumbled, resulting in violent outbursts and a loss of control over his kagune, which began to encase his body. He was tended to by his servants, Kanae von Rosewald and Matsumae, a period which highlighted the absence of his own family. Learning that Kaneki was alive—operating as Haise Sasaki within the CCG—precipitated a rapid recovery. He confessed that his feelings for Kaneki had evolved beyond seeing him as food and expressed a genuine desire to help him regain his memories. This marked a maturation in his character; he grew more humble, expressed gratitude and a sense of responsibility toward his servants, and showed concern for others like Hinami Fueguchi. His family was targeted by the CCG in the Tsukiyama Family Extermination Operation. Cornered by Sasaki, he was allowed to escape despite fatal injuries. In the aftermath, he joined the organization Goat as a direct subordinate of the One-Eyed King, Ken Kaneki, and fought in the Rushima Landing Operation and the Dragon War. Six years after the conflict, he became a leader of the United Front alongside Kazuichi Banjou and Ken Kaneki. He possessed a tall, attractive physique, purple hair, and dark purple eyes, and was typically adorned in flamboyant European-style suits. His severe depression ravaged his appearance, leaving him emaciated with unkempt hair and nails, though he later regained his former look. His kakuja was a bright purple ukaku type, lined with red veins, and his mask featured a crescent moon design. Beneath the flamboyance lay a deeply lonely individual. His eccentric personality served as a subconscious coping mechanism, developed from a childhood devoid of parental attention and close friendships. He sought acknowledgment through academic achievement and cultivated his interests through books. His unusual dynamic with his human friend, Chie Hori, whom he referred to as a "pet," and his close bonds with his servants further illustrated his struggle with normal social connections and his enduring experience of loneliness.