Toma is handsome with light brown hair and light eyes. He is 189cm tall with a muscular body. He is almost always seen with a smile on his face.
Toma is a pure-hearted and happy-go-lucky person with an even temper, and generally possess a positive attitude. His good nature allows him to get along with everyone, even those considered to be outcasts. Because of this, he has a huge and varied group of friends.
He is incredibly athletic and was the ace of his school's baseball team. Being a baseball pro was the only dream he ever had but it was put to an end when he broke his leg while saving Taichi from an oncoming car. However, he does not regret his decision; he believes life has more value than any dream he could have.
In order to maintain his friendship with Taichi, he represses his romantic feelings and cheers on the budding relationship between Taichi and Futaba Kuze.
He is a gentle giant with a heart of gold who genuinely wants the best for all his friends, wanting to protect them from getting hurt even if it means getting hurt himself.
Sometimes, he is compared to a big friendly dog. Futaba has said that she finds his large frame very cute since it makes everything around him look small.
When Toma was eleven, his parents died in a car accident trying to avoid a child on the road, leaving him in the care of his college-age brother, Seiya Mita. This resulted in Seiya working hard to support them both but, in turn, he ended up somewhat neglecting the house and Toma. Toma often tried to help his brother out but at his young age was unable to do much.
His ex-tutor, Akiko, ended up helping them out and eventually, she and Seiya started dating and got married. Worried that he was now getting in the way of Seiya and Akiko's life together, he ended up getting into an argument with them and running away to Taichi's home. When Seiya came over to bring him back, Taichi, seeing how much Toma did not want to go home, shoved Seiya to the ground and ran away with Toma. Even though he was caught and brought home in the end, this remained one of Toma's fondest memories.
While in elementary school, he created a handmade "game of life" board game with Taichi where the person with the most points was the happiest.
He decided that he wanted everyone playing the game to be happy, so he created a square where everyone playing the game gained 10,000 happiness points through best friend power.
Despite being in love with Taichi, Toma remained closeted in order not to upset the status quo and actively encourages the blossoming relationship between Taichi and Futaba. However, when he was outed after Kensuke found out about his sexuality, he decides to tell Taichi about his feelings before leaving school.
Masumi Itachi asks him if he thought coming out to his peers was worth it, and said he was lucky his friends were still his friends. However, he tells her that their decision to remain his friend were a direct result of him choosing to be his true, authentic self and them accepting him for who he is.
Unsatisfied with how things were left between them, Taichi and Futaba go to visit him at his home, only to find out that he moved away a few days before to be closer to his construction job. They take the train and look for him at his job site. When Taichi confronts Toma, they talk about their friendship and make the decision to remain friends while Taichi chose to remain with Futaba.
Sometime in the future, it is revealed that Taichi and Futaba break up two years after completing high school due to various reasons causing them to grow apart. Toma and Taichi eventually marry with Toma taking on Taichi's surname. Toma remains in close contact with Futaba and Masumi as well as Kensuke and Shingo, and was the one that encouraged Taichi to meet up with Futaba again and mend their friendship. He attends Futaba's wedding and she tells him that the three of them are still her greatest inspiration.
- The characters in Toma's name have a couple different meanings:
- "Toma" means "peach" (桃) (tou) and "real/genuine" (真) (ma).
- Toma's surname, "Mita", means "three" (三) (mi) and "field/rice paddy" (田) (ta).
- Toma maintains a friendship with Futaba Kuze and Masumi Itachi.
- Toma is the only one out of the main cast that is not actually seen in the final chapter because we are viewing the event from his perspective.