He has a very unique hairstyle: blue eyes and platinum blonde hair with a blue gradient, layered medium-length hair that splits into two long sections at the back, inspired by a bird's tail. He has a V-shaped cowlick similar to Ness and Isagi. There is a red tattoo under his eye, and his eyes are sharp. A blue rose tattoo is on the left side of his neck, with rose vines extending down his arm, and a crown tattoo with a lock design is on the back of his left hand. Psychologically and as a human being, he is quite broken. His behavior is that of an adult who hasn't grown up mentally. Among the Blue Lock characters, he has particularly large mood swings and expressive facial changes. Because he is arrogant and loves to provoke others, he might seem like a sly, smiling character when he's emotionally relaxed, but his actual personality is cold and short-tempered. While his pride is sky-high, his self-esteem is extremely low, showing the negative aspects and obsessive tendencies often found in perfectionists. He even struggles to view himself as human; his monologues reveal a bottomless abyss of self-loathing. Despite the trouble he causes on and off the pitch, he is a forward selected for the New Generation World 11 with significant authority and fame. His talent and skill are recognized as top-tier by the current world's best and second-best players. Kaiser was born to a director of a small theater troupe in Berlin and the troupe's lead actress. His mother named him Michael and left immediately after birth. While his mother became a successful Hollywood actress, his abandoned father became a wreck, consumed by loss, alcohol, and gambling. Kaiser grew up suffering severe abuse, forced to steal for a living while enduring violence and verbal abuse. He strokes his own neck as if strangling himself whenever he feels anxious. Toward his girlfriend, he is sly, unhesitating with physical affection, and loves to tease her.