Mitsuo (ミツオ, lit. Mitsuo) is a supporting character and a minor antagonist in Parasyte, as well Kana's ex-boyfriend.
Appearance
Like a large majority of characters in the series, his design in the anime greatly differes from his original appearance in the manga. In the manga, Mitsuo is a large muscular young man, who has slicked-back black hair and a strong jaw line. In the anime, he has brown hair, stubble on his chin and wears a black hooded jacket inside a red mantel, and a dark-gray skullcap. He appears less muscular in the anime.
Personality
Mitsuo is easily aggravated and is quick to start fights, though it seems he deeply cared for Kana, as shown when he was crying at her funeral and attacked Shinichi for being unable to protect her. His feelings were hurt when Kana said she no longer cared for him and that leave her alone.
Also, Mitsuo does hold a hatred towards Shinichi due to the latter not only for not being able to save Kana, but he didn't shed tears for her death, causing him to be saddened and increase his dislike for Shinichi. When he tries to punch Shinichi for this and telling him he's not human, Shinichi angrily reacts by agressively punching Mitsuo's face, beating him to the ground and causing both his mouth and nose to bleed, as Mitsuo starts to cry.

