Sanzu Haruchiyo

Sanzu Haruchiyo, a key character in Tokyo Revengers (especially in the Bonten and Kanto Manji arc), is characterized by an androgynous and deceptive appearance, and a personality that is extremely loyal to the point of madness, manipulative and sadistic.
Here are the details of his physical appearance and personality based on the manga/anime:
Physical (Appearance)
Hair: He wore his hair short as a teenager, but as an adult (Bonten), he wears a long mullet that reaches his shoulders, usually dyed light pink (rosy pink) in the manga, although in the anime it sometimes appears platinum blonde.
Eyes: It has droopy eyes with long eyelashes, giving it a deceptively docile appearance.
Scars: His most distinctive feature is two deep scars on either side of his mouth, reminiscent of a Joker smile (Glasgow smile style). These scars are the result of past trauma involving Mikey.
Mask: For much of the series (especially in Tenjiku/Toman), he wears a black mask to hide his scars.
Height and Build: He is of average height (approx. 172cm as a young man, 181cm as an adult) and usually has a slim build.
Style: He usually wears elegant formal suits as an adult (Bonten) or the Kanto Manji uniform. He has piercings in both ears (four in each ear in his adult stage).
Personality
Fanatical Loyalty: Her main trait is her absolute devotion to Manjiro Sano (Mikey), whom she idolizes as her "king." She does everything for "Mikey's will."
Psychopath/Deranged: He is sadistic and ruthless. He enjoys inflicting pain and feels euphoria when executing traitors.
Manipulator: Although he appears chaotic, he is extremely calculating and strategic. He uses his appearance and reputation as "crazy" to lower enemies' guard, manipulating others (as he did with Mudo) to achieve his goals.

Here are the main details about what Sanzu Haruchiyo is like:
Personality and Behavior: He is possessive, arrogant, and cunning. His intelligence is reactive and strategic, using chaos to achieve his goals. He shows extreme devotion to Mikey, not hesitating to eliminate anyone who betrays his "king."
Physical Appearance: As a young man, he is depicted with pink hair in the manga, although in the anime it is more of a bleached blonde/white. As an adult, he sports a mullet haircut and usually wears Bonten-style clothing, often with a black mask that covers his scars.
History and Scars: The scars on his mouth are the result of a childhood incident where Mikey attacked him for destroying a toy figure. Despite this, his loyalty to Mikey remained unwavering.
Abilities: He is a lethal fighter who uses katanas or blunt weapons. Capable of facing strong opponents, he even surpassed his younger sister, Senju Kawaragi.
Relationships: Although he initially formed a close bond with Muto, he showed no mercy by killing him after a betrayal.
In summary, Sanzu is a complex and chaotic character who mixes apparent mental instability with absolute and tactical loyalty, making him one of the most unpredictable villains in the series.

Sanzu Haruchiyo, a character from Tokyo Revengers, is known for being manipulative, obsessively loyal to Manjiro Sano (Mikey), unstable, dangerous, and cruel, often described as "unhinged." He is characterized by his striking appearance with long hair, scars at the corners of his mouth (frequently hidden by a mask), and expertise in the use of bladed weapons in combat.