Moriyama has short black hair with a green tint that he parts to the right. His eyes are very narrow and he is of average build. On the court he wears the blue and white Kaijō jersey with the number 5, outside he is normally seen wearing his school uniform.
Moriyama is a ladies-man and he likes to flirt with girls. He constantly looks out for cute girls and plays basketball for their sake. That said, he can be silly at times, but is focused, reliable, and serious when he needs to be.
Moriyama appears for the first in the Kaijō locker room before their Interhigh game against Tōō High, still daydreaming about a girl he saw in the stands. When the match starts, Moriyama is a starter and lines up with the rest of his team. The tip-off is given and the ball goes to Tōō after an Aomine's steal. Wakamatsu swings the ball to Sakurai, who shoots with a very quick release and Moriyama is unable to block the shot. Later, at the end of the first quarter, after a bad shot by Kasamatsu, the ball goes from Hayakawa to Moriyama, who pulls up for his unique, bad-rotation shot and nails it.
At the 1st quarter break, he congratulates Kise for stopping Aomine but he replies that things are only get started yet. Aomine quickly turn the tide and begin to widen the gap. During Kaijō's timeout, Kise says he'll try copying Aomine, to Moriyama's and his team-mates surprise. Kaijō is determined to gain time for their ace and has to keep up as long as possible. After Aomine's foul on Kasamatsu, Moriyama somehow doubts Kise's ability to copy Aomine. Kasamatsu replies that they have to believe in Kise. 
Moriyama desperately blocks Sakurai three-pointer in the 3rd quarter, to stop the gap from widening. Kise is amazed by his determination but Moriyama tells him to focus. He further adds that he'll have to introduce some girls in a party if they win, something that Hayakawa disapproves.
Moriyama then witnesses his team's ace Kise copying Aomine and the battle between the two. Before the 4th quarter, Moriyama asks him if he's fine. Kise responds affirmatively but Moriyama insists that the team will need him in defense even if Aomine will be excluded. Kaijō slowly catches up to the score but Kise is finally beaten near the end of the match by Aomine. Nevertheless, Moriyama and his team-mates comfort him. The match ends a 98-110 for Tōō.
Moriyama and his team-mates are disappointed, but more importantly, he sees that Kise struggles to stand up. Moriyama blames that to his copy of Aomine's play. Kise is helped by Kasamatsu and then line up with the whole team. After leaving, Kise notices that Kasamatsu is not with them. Moriyama replies that he asks them to leave first. Kise says he'll wait for him but Moriyama tells him not to, and to leave him alone.
At the Winter Cup, he plays with Kaijō in the first game of the Cup. He is also seen watching Seirin's quarter-finals and warms up when it's their turn. Hayakawa notices Kise's determination. Moriyama tells him that the main cause of it may be their next opponent, because of his reaction when viewing a video data of them.
The Winter Cup quarter-finals against Fukuda Sōgō Academy commences and the first ball possession goes to Kaijō. Moriyama gets the ball from Kasamatsu and shoots his unorthodox shot, getting the first three points of the game. A little later, Haizaki copies Moriyama's shot, but tweaks the rhythm. When Moriyama tries to do his shot again, he subconsciously loses his rhythm and misses. Haizaki has stolen his move.
The match progresses to the fourth quarter and Kaijō is struggling. Without the back-up of their ace and the difficulty of using their specialities, Moriyama's team has fallen back to a good 15 points. After Kise awakens his Perfect Copy and pushes back Haizaki, he leads the team to victory.
His team later goes against Seirin. On the pitch and as usual, Moriyama is peeping at the spectators for cute girls. Hayakawa asks if Moriyama is being serious but he answers he has been looking forward to this and is so focused that none of the girls are interesting him. Through the first half, Moriyama is often seen guarding Hyūga and scoring some three pointers with his unorthodox shot.
In Kaijō's locker room at half-time, Kise is demanding to be subbed in again, as he is the only one who can face Kagami and asks for Moriyama's support. Moriyama feels guilty for almost saying to put him back, because of the lack of alternative to Kagami's two man-mark. The issue is settled by Kasamatsu who didn't allow Kise's entrance before the end.
The match continues with the second half: Kaijō is hanging on, with Moriyama scoring more three pointers. Hyūga comments on how his shots are impossible to guess. Moriyama's shot are eventually blocked by Hyūga who matches his timing. Kise is later subbed in again for the last 4 minutes, and Kaijō is going all out. Moriyama and the other are hardening their defense. He steals the ball from Izuki, and thinks to himself that Izuki is unusually too obvious. At the last second, Seirin manages to win. Close to tears, Moriyama and the others wish luck to the winners for the finals.
Without their ace, Kaijō is powerless and loses to Shūtoku for the third place. Moriyama and his team-mates then arrive to watch Rakuzan versus Seirin already in the third quarter, only to see Seirin in a hopeless situation. 
Moriyama focuses mostly on shooting. Moriyama possesses an Unorthodox Shot (modified underhanded set shot) to score three-pointers. He throws the ball underhanded, which gives a very high arc and almost no rotation to the shoot. According to Sakurai, his shooting form is unique, as if he has a bad rotation. This was further explained during the quarter-finals of the Winter Cup. This form is apparently the most comfortable way for him to shoot and creates an unusual form that is hard to block. Hyūga comments on how it became his own personal weapon.
- Moriyama ranked 24th on the second character poll, with 117 votes.
- In Replace, he was nicknamed and known as the "Pitiful Handsome Guy".
- In one of the bloopers, Moriyama asks Kise to set up a party with girls, but that he shouldn't come in it, telling that he'll get all of them if he does.
- According to the CHARACTERS BIBLE:
- His motto is "Ladies First".
- His favorite food is Kitsune Udon.
- His hobby is playing futsal.
- His specialty is palm reading.
- His best subject is Mathematics.
- He has a father, mother and an older brother.
- He doesn't like girls who are too trashy.
- He spend his days off by playing futsal with his friends.
- He started to play basketball because he had heard that basketball is popular with girls.
- He player he has his eyes on is Hyūga.
- Historically, the underhanded shot was popular in the 30's-70's amongst guards and forwards, but there was very little arc then. Rick Barry used this for his free throws. Harlem Globetrotters holds the Guinness World Records for the most underhanded half-court shots in a minute, and the longest underhanded shot.
|Players||Ryōta Kise • Mitsuhiro Hayakawa • Shinya Nakamura|
|Former players||Yukio Kasamatsu • Yoshitaka Moriyama • Kōji Kobori|