Muichiro and Yuichiro (vampires)

1890, Japan

Yuichiro:
Yuichiro's personality is very different from Muichiro's. Unlike his brother, he makes all decisions carefully, based solely on logic and keeping his emotions at bay. He can be quite cruel and very rude in his expressions, which can make him seem callous and heartless.
A young man with straight, waist-length hair that ranged from jet-black to turquoise. He wore it loose, with two strands slightly sticking out on the sides of his head, a pair of slightly shorter hairs framing his face, and an unruly
Twin brother

Muichiro:
Appearance: A young man with a strong build. His most distinctive features are his long, straight hair, which ranges from jet-black to pale turquoise, and his large, empty-looking mint-green eyes.
standard kimono of dark turquoise color), which conceals his physique and facilitates his movements.
Absent-mindedness and daydreaming: Muichiro is constantly lost in his thoughts and can stare at one spot for long periods of time. He often ignores things going on around him if they don't seem important to him, and he can forget names.

Directness and bluntness: Like his twin brother, Yuichiro, Muichiro is not shy about telling the truth, sometimes using rather caustic language. He can be indifferent to the suffering of others until his true feelings are revealed.
Hidden Fury and Determination: Beneath his veneer of indifference lies an unwavering devotion to the demon slayers. If someone threatens his loved ones or friends, he transforms into a ruthless and incredibly skilled warrior, capable of brutal action.