Teshima Junta is a second-year student at Sohoku High School and a member of the Sohoku High Bicycle Club. While he is unable to make the Inter High team during his second year, he was announced by Kinjou Shingo to be captain of the cycling club during his third year and beats his teammate and old friend Koga to secure his spot on the Inter High team.
Teshima has fairly long, wavy hair, which he sometimes wears back in a ponytail. In pictures colored by the mangaka, he is depicted with shades of blue and purple in his hair and eyes, and he is initially depicted with much curlier hair. In the anime, Teshima's hair is solid black. For the movie, Teshima is given more violet-toned hair and blue eyes. He is often shown wearing shirts with star designs on them. In year three, his design also feature English teaspoon, small milk jug and tea cup.
Teshima is very smart and uses strategies to win races along with his close friend Aoyagi. Seemingly nonchalant, condescending, and teasing at first, he acts subtly hostile towards the first-years to prevent them from joining the Inter High team. It's shown that Teshima has a complex as an "ordinary" cyclist that cannot reach the top world of "elite" cyclists, which is why he works with Aoyagi as a "team of two". He is a thoroughly hard worker, but doesn't have much confidence in his own cycling abilities and easily resigns himself to his status (and nearly quits cycling because of it) before entering high school and witnessing an Inter High race. Teshima tends to damper his emotions when things go wrong, accepting failure as the fate of someone "ordinary", but he has a fierce, competitive desire to win and can become quite emotionally charged when he refuses to accept that he's unable to achieve anything.
As it turns out, Teshima is very humble and supportive of Sohoku's cycling team after his loss, even to those who've personally defeated him. It's as if his hostile nature beforehand was circumstantial, simply born from his desire to win and ride with his mentor Tadokoro before the third-year graduated. During downtime with the first-years, it's shown that they've reconciled their differences and have bonded with him and Aoyagi, and he takes his role on the support team during the 41st Summer Inter High very seriously. He's willing to physically push team members who've fallen behind and ease their mental state from the reality of their situation. Teshima believes in his teammates, and encourages others (particularly Sugimoto, Naruko and Onoda) to believe in them as well.
After Inter High, when he became the captain, he has become very adept at encouraging Imaizumi and Naruko, namely to convince the former to spend more time to discover and compliment Sadatoki's effort and talents, and allow the latter to take indefinite leave so Naruko can consider his future as a sprinter in Osaka.
He also uses his own psychological warfare to psych out opponent and cast doubt over his own teammates (even when the person in question or is 'uncertain to make the team' is actually himself), as shown by the 1000km training camp when he explained that he is the unconfirmed member rather than Kaburagi Issa when he races against Koga Kimitaka as they settle old scores. He also likes to state the obvious, but is also good at putting the obvious into practice, which are mostly the fundamentals.
Skills and Techniques
Since Teshima isn't a particularly strong cyclist, he relies on his wits as a strategist, able to predict when other cyclists will overcome any handicaps during the Training Camp. He is also shown then to be good at blocking people from passing him, able to hit another's bike to knock them aside without falling himself, and he implies that he usually blocks people so Aoyagi can break ahead and take the goal.
Having been on the support team for the previous Inter High as a first-year, Teshima is quite experienced in what needs to be done.
According to Makishima, he believes that Teshima has what it takes to be a climber, but he has mediocre technique and instinct. Also, he is better suited as a climber because he is weak as an ACE sprinter as he has never won a sprint finish in official races.
Teshima and Aoyagi both have far better-developed leg muscles as they trained hard after being scratched from the 41st Inter High. After that, when they were named as Captain and Vice Captain, they took out the sprint race by brute force over the first years.
In the Minegayama Hill Climb Race, he was the only one able to keep up with Ashikiba Takuto by increasing his cadence to a faster rate than both Onoda and Imaizumi, given Takuto went from the back to get to the front with nearly 4km to go, the point where they normally had to stop. Their competition also affected the first years, including Naruko, as he started to respect him because it is the first time he raced 'solo' without Aoyagi (who is a sprinter). He also showed his mental game when asking Onoda if Ashikiba reminded him of Makishima due to their similar riding style of swaying the bike violently. It helped to push Onoda beat Ashikiba win the Minegayama Hill Climb Race with less than 800m remaining.
In the Inter-High Qualifiers - Chibi, Teshima provoked the leading pack that he will get the bottle back and catch them in lap 9 before winning the race, which they did. Naruko commented that Teshima doesn't mentally provoke opponents much, but he is effective when he does so.
- Singing in the shower
- Karaoke (likes J-pop, in episode 2 of season 3, Higashida, from the volleyball team, formerly from middle school cycling team, likes hearing his medley of impressions.)
- Sports manga
- His bed after practices. According to Episode 24 and Omake 24 of season 3, he thought about his bed when he had a concentration lapse, and he crashed into his bed after he finished his 1000 km at training camp, and skipping dinner altogether.
- Best subject
- Math (competed in a prefectural abacus tournament when he was in middle school)
The bond between Teshima and Aoyagi is so strong, Teshima can guess what Aoyagi is thinking before redicting the conversation, leaving Onoda puzzled and making Naruko think Teshima is psychic (telepathic). In turn, even though Aoyagi doesn't race in Hill Climb races, he knows exactly when Teshima reached his limit.
In the preview to the second episode of Season 3,Teshima Junta served Afternoon Tea with flair to the 1st years, suggesting both him and Aoyagi worked as waiters part time. In the preview to the 15th episode, Teshima worries that his hair can't be as straight as Aoyagi, which is doesn't as it is so wavy.