Tatsuma Mido Edit
He is often scene shirtless or basically naked aside from a pair of pants/speedo. I'm not really sure what he wears. I think it's to make sure people don't mistake him for a woman when he doesn't want to be.
Gakuen Taikutsu Otoko Edit
Known as Guerrilla High, Tatsuma Mido is partners with Mondo Saotome, although this partnership is more so on-off. They are seen working together infiltrating a school at the beginning - with Saotome in a regular boys uniform, and Tatsuma in a girls uniform.
In the series, it is revealed that Tatsuma is a clone of Toranosuke Mido - who at first is known just to be Tatsuma's twin brother. Toranosuke is seen with cloth wrapped around his face to hide a deformity caused by Tatsuma. Tatsuma poured acid on Toranosuke's face while he was sleeping to create this deformity - this was out of jealousy of Toranosuke being the favorite brother.
When Tatsuma's parents reveal he is a clone, Tatsuma sets their house on fire out of rage, killing the parents and presumably Toranosuke.
Violence Jack Edit
In Violence Jack, Tatsuma is introduced as Mondo Saotome's partner from back in the day, and together, they partner up again.
They escape from jail together and go on a few little adventures here and there - with Tatsuma often being mistaken for Mondo's girlfriend. They typically fight back-to-back, defending one another. Mondo and Tatsuma are seen touching each other by either hugging, or in one instance, Tatsuma is riding on Mondo's back as Mondo swims to land (since Tatsuma cannot swim).
It's a reoccuring gag of Tatsuma being mistaken for a girl - even Mondo is guilty of doing this by saying "You look like a bitch" to Tatsuma while in the bath, and goes on to think perverted thoughts about Tatsuma if Tatsuma were a woman.
In the Hyper Grapple arc its revealed by Susano'Oh that after Mondo bit it, Mido used his psychic powers to create a fake Mondo. Susano'Oh is mad that Mido has such psychic powers and Mido being in Future City is clashing with his powers off keeping the illusionary city up and tried to have em whacked but after Mondo slags the attackers, has his Loli Daughter bring them in and talk. As a psychic battle (Like in South Park with Cartman nananana-ing at the psychics?) would be tough and cause him to lose concentration keeping the city up, he trys to talk em into leaving but later decides to ice em with his powers of summoning naked dr's to vivisect Mido. Violence Jack comes to the city and f's things up and Mido and Mondo escape and after the city vanishes, swim to the wasteland. Mido is worried of Mondo being
In the Shadow Realm dead but Mondo says maybe its some kinda Alternate Reality thing and in 1 reality he's alive and another he bit it. This revives Mido's spirits and they go to the wastelands together.
In the end of the volumes involving both Mondo and Tatsuma, it's basically revealed that Tatsuma is in love with Mondo as he runs away with Mondo's head after Mondo is killed by Violence Jack.