He is one of the students in Class 1-A at U.A. High School, who is training to become a Pro Hero.
Ojiro appears to have olive skin and short blond hair. His mutant-class quirk gives him an extra appendage-- a tail. The tail also has bushy, brown hair on it's end.
His hero outfit looks almost identical to a karetegi, with a black belt complementing it. He also has black boots and sometimes blue gloves.
Ojiro carries a sense of dignity that makes him only wish to achieve his goals honorably. He dislikes accepting results he feels he didn't work for. Ojiro works very hard to become a hero, to overcome the undesirable quirk he has that makes sitting down and laying down difficult for him. Working hard for his achievements likely gives him a sense of pride, making training one of his hobbies. However, he is not a prideful person at all, and is shown to be very humble. This humbleness also makes Ojiro believe that his classmates are also very respectable.
Ojiro has shown to be unwilling to progress if he believes that he hasn't given it his all. This is shown when he withdrew from the fighting match of the Sports Festival, having been under the control of Hitoshi Shinso's Quirk and saying that he didn't earn his right to proceed forward in the tournament.
A running gag is others commenting on Ojiro's style as "plain", something that upsets him as shown during the room presentation contest.
Mashirao's Quirk "Tail" gives him an incredibly strong prehensile tail. While normally this quirk wouldn't be effective, he has devoted his time into training this seemingly undesirable quirk into something that enhances his fighting prowess. The tail can act as an extra appendage to assist Ojiro in combat.
- Tornado Tail Dance - Ojiro spins in midair, attacking everything around him with his tail.
- Fist of the Tail: Swamp Smack Spin - Ojiro spins his tail while on the ground, repelling everything around him.
- Ojiro's favourite thing is martial arts, which is shown with his fighting style and hero costume.
- Horikoshi claims that it's impressive for him having passed the U.A. Entrance Exam with just a tail Quirk and labels him as a hard worker.
- Horikoshi explains that people with mutant appendages like Ojiro's tail have their clothes custom-made.