Kaname Yamazaki is an 18-year-old male with silver hair and cyan eyes, standing 171 cm tall. Born on August 31, he regularly stays with the Kujo family. Academically exceptional, he achieves top-tier rankings in nationwide mock entrance exams yet deliberately avoids first place to evade attention. He attends school pragmatically, viewing it solely as a path to graduation credentials, and finds all subjects unchallenging and uninteresting.

He expresses indifference toward any reappearance of his biological parents. His stated aspiration involves a future in a white house with a dog, his wife, and children. He develops a relationship with Rei Izumi, a 26-year-old colleague, displaying protective behaviors like driving her home and engaging in thoughtful conversations. During these interactions, he reflects on his role as her boyfriend and strives to maintain composure, consciously avoiding physical affection when concerned about self-restraint.

He anticipates his 20th birthday as a significant milestone linked to adulthood and deepening his bond with Rei, privately feeling impatient about the year-long wait. His association with the STAND unit involves him in professional narcotics investigations, though operational specifics remain undefined.