Shun Izuki (伊月 俊 Idzuki Shun) is a second-year regular point guard and vice-captain at Seirin. His signature ability is the Eagle Eye, which helps him keep track of the court and tailor his team's plays accordingly.
Izuki has straight black hair that reaches his eyes. His eyes are narrow and resemble an eagle, which hints to his ability. His eyes are also usually shown without pupils, entirely black. He has a rather small and athletic-looking body, in contrast to his teammates. He plays with the jersey number 5.
His appearance hasn't changed much from the previous year, but in his first year in high school, his hair was shorter and parted on the right side.
On the outside, he has a cool attitude, but on the inside, he has an unfortunate hobby for puns or dajare (word-jokes relying on similar pronunciations). Apart from his puns, he is also very smart. He plays his matches with a cool-headed personality. He is an excellent strategist. Izuki is also loyal to his friends, shown as he followed Hyūga to Seirin so he would have some company, despite knowing that the school did not have a basketball team, the sport Izuki was so passionate about.
Izuki has played basketball the longest of all the members of Seirin, having started with mini-basketball in second grade. His passion for the game is stated by Hyūga to be the greatest of them all. Izuki is shown to have played middle school basketball with Hyūga and is disappointed that his friend has decided to quit basketball after a disappointing middle school record because of the Generation of Miracles. Nevertheless, despite knowing that Seirin does not have a basketball team, he follows his friend to the school, not wanting Hyūga to be alone. Izuki is excited when Kiyoshi proposes that they start a basketball team, and is on board with the idea. Along with Kiyoshi's help, Izuki and the other Seirin members try to recruit Hyūga, but most of their attempts fail. In the end, Izuki is delighted to learn that Hyūga is joining their team.
He is seen showing concern when Hanamiya injures Kiyoshi during their match against Kirisaki Daiichi.
Seirin vs Kaijō
Semi-finals: Seirin vs Seiho
It is then shown what Izuki's talent is: the Eagle Eye. Kasamatsu commented that he is the key playmaker of Seirin High. After he makes the shot, he made a pun to Hyūga, prompting Hyūga to threaten Izuki by subbing him out.
Finals: Seirin vs Shutoku
The finals of the Interhigh preliminaries are about to begin and Hyūga fires the team up. The match commences and Kagami and Ōtsubo jump for the tipoff. The ball goes from Mitobe to Izuki and Izuki passes to Kuroko, who redirects the ball to Kagami for an alley-oop. Midorima blocks, Takao drives the ball upcourt and faces Izuki. Takao passes behind his back and foils Izuki's defense.
The match continues and Takao goes up against Izuki yet again. Takao uses his speed to cross Izuki, while Izuki can only be amazed at Takao's fast movements. Takao passes behind his back to Ōtsubo, who's open and Izuki wonders if he has a Eagle Eye too. When Takao blocks Kuroko's pass, Izuki realises and confirms Takao's ability. He tells Hyūga that Takao has the Hawk Eye, an even stronger ability than Izuki's. He says that Kuroko's misdirection won't work against Takao. Izuki confers with his team before facing off against Takao once more.
He appears at the Winter Cup alongside Seirin at the opening ceremony and while entering the field. At the tip-off for their match against Tōō Academy, he receives the ball from Kiyoshi. Following Riko's orders to score quick and strong, Izuki dribbles up the ball fast, but runs into Tōō's pressure defense. Unexpectedly, Tōō doesn't underestimate Seirin and Izuki is covered tightly by Imayoshi. He tries to pass to Hyūga, but the ball is stolen by Sakurai. As Sakurai and Aomine perform an alley-oop and the first point is scored, Izuki passes the ball back into the game to Kuroko, who prepares for his Ignite Pass Kai. Kagami scores and Izuki is seen guarding Imayoshi before he passes to Susa. After Kagami's simulation battle with Aomine, he passes to Izuki. The ball eventually goes out of bounds and Seirin calls for a time-out. During the meeting, Izuki says that they're stuck in a rough battlefield. Hyūga says that the solution is him scoring a few three-pointers and tells Izuki to pass to him. When gameplay resumes, Izuki passes and Hyūga does indeed score. Both Hyūga and Sakurai continue to shoot until the first quarters end.
At the beginning of the second quarter, Izuki passes the ball to Kuroko who attempts a Vanishing Drive on Aomine, but fails. Izuki passes the ball to Kuroko once again, but realizing that he was going for an Ignite Pass Kai, tries to warn Kuroko that neither Hyūga nor Kiyoshi have gotten away from their marks. Trying to get the team to calm down, Izuki passes the ball to Hyūga but is intercepted by Wakamatsu who performs a lay-up. As Kuroko stays on the bench from being subbed out, Izuki and the rest of Seirin are surprised at Kagami's skill being able to keep up with Aomine.
During the beginning of the third quarter, Izuki is surprised because his mark changed from Imayoshi to Susa. Imayoshi then blocks Izuki's pass to Kuroko and shoots a three-pointer, surprising Izuki. Izuki then passes the ball to Hyūga for him to attempt to make a shot. As the third quarter almost ends, Kuroko's Misdirection runs out, and Imayoshi goes back to guarding Izuki. The teams spirit does not falter and Izuki tells Imayoshi that they let Kuroko's Misdirection run out. Izuki dribbles the ball and disappears from Imayoshi's sight, appearing behind him and scoring a point. Seirin pulls out their final trump card, Misdirection Overflow. Even with the use of Misdirection Overflow, Imayoshi shoots a sudden three-pointer from across the court, taking Izuki by surprise, and ending the third quarter.
During the fourth quarter, Seirin's defensive strategy turns into a Zone Press. Aomine then enters the Zone making Izuki's passes intercepted by Aomine. Izuki tries to drive past Imayoshi with the Misdirection Overflow but it begins to start to run out. As Kagami enters the Zone, Izuki and the rest of Seirin leave the game to Kagami, in which they win the game.
Izuki can shoot, pass and dribble on a high level. According to Hyūga, he started playing basketball in second grade, the earliest compared to anyone in Seirin. Izuki doesn't have any specific offensive skills, but he is fast and agile, able to change direction while dribbling and foiling his opponents easily, and also uses his speed in making easy lay-ups during fastbreaks. He has also been seen to successfully shoot a three-pointer. Despite being at a position where he can rarely shine, Izuki is nevertheless important for Seirin's attack patterns, supporting his team from the shadows. He is nicknamed the "control tower" of the team. A chart of his skills were included with his profile in the CHARACTERS BIBLE. His stats are balanced but he excels in technique. His levelheadedness during games is fundamental to Seirin's gameplay, as seen against Rakuzan during the last moments of the Winter Cup finals.
During Seirin's finals in the Winter Cup, against Rakuzan, Imayoshi observes that Izuki managed to improve himself in the middle of the match, mirroring the transformation of the Uncrowned Kings of Rakuzan. He succeeded in stopping Hayama's four-fingers dribbling, which even Kagami or Miyaji (against three fingers) couldn't have done. Though failing to stop the five-fingers all by himself, he successfully lured Hayama into Kagami's large sphere of defense with Kuroko's help because he knew that he wouldn't be able to match his speed. His intelligence led Hayama to label him as a top-tier player. His ability to think ahead was also a key factor in Seirin managing to cut the deficit against Rakuzan to 1 because of his correct prediction that led him to steal the ball. At the same time notable players in the crowd noticed that the pass he gave to Hyuga was perfect and seemed like Akashi's,
As a point guard, Izuki possesses a very useful ability. Using his Eagle Eye, he can see the basketball court from a different perspective. As if he watches plays from above, he can see the formation of all the players and develop a strategy accordingly. Practically, he can use it to pass efficiently, make blind passes, and move so that two of the opponents collide with each other.
However, the Eagle Eye has a blind spot unlike the Hawk Eye, which Mayuzumi takes advantage of, though even with this blind spot he is able to suppress Mayuzumi. Izuki's vision also allowed him to predict Hayama's Lightning Dribble, to the point that Hayama needed to use all five fingers to pass him.
While not to the level of the Emperor Eye, Izuki can still use his Eagle Eye to predict his opponents' actions. However, this doesn't always work if his reaction time fails to match up to his opponent's speed, as seen by how he was unable to keep up Hayama's movements during the Rakuzan player's five finger dribble.
After getting a sense of the opponents speed, Izuki can steal the ball from behind his back, without looking, against a much faster opponent like Kasamatsu. He uses his Eagle Eye to see the position of the ball and locate the opponent. By not turning his body and simply lunging his arm to the desired direction, he can stop high speed drives, associated with his ability to think ahead before the opponent. He learned this from Kagetora during the Winter Training Camp.
- "Nice. I’m impressed, Mitobe." 
"Nice. Mitorechau Mitobe."
- "Point guards with lower specs have to use our heads!"
- "A camel told me... compared to Akashi, you're just a hump in the road."
- "I'm just glad you weren't smarter than me."
- On the first character poll, Izuki ranked 5th, with 955 votes. He dropped to 7th place on the second poll, with 618 votes. He later dropped to 13th place, with 851 votes.
- According to the CHARACTERS BIBLE:
- His favorite food is coffee jelly.
- His hobby is making puns.
- His specialty is making 100 puns in a row.
- His motto is: "Always Flexible."
- His best subject is Math.
- He is part of the school's disciplinary committee.
- He has a father, a mother, an older sister (Aya), and a younger sister (Mai).
- His best basketball move is steal.
- His type of girl is a girl who understands puns.
- He spends his time off by taking the dog for a walk.
- He started playing basketball in order to acquire physical strength because of mini-basketball.
- The player he has his eyes on is Takao.
- Izuki's mother has the same love for puns as himself. In fact, both of Izuki's sisters share this trait too.
- When the team was cleaning out their lockers, it is seen that Izuki gets his jokes from a series of joke books, that go all the way up to volume 108. Seirin’s members were able to find puns about all of them; however, Hyūga didn’t find any on himself. (Vol. 107 is missing) 
- On last year's test results, he ranked 71st out of 300. His best course is math.
- According to a Q&A section, Izuki is the most popular with girls on the team, but they all run away once they see his joke book.
- Izuki is the vice president of the “School Life Guidance’s” committee. 
- The reason why Izuki's name is often shown as "Iduki" is because the hiragana in his name are actually pronounced "Idzuki" and the "dzu" is changed to a "du".
- Hirofumi Nojima, the voice of Izuki, also voices the barks of Tetsuya #2.
- Izuki is one of the two Seirin players who has played in all competitive matches seen so far (the other one is Junpei Hyūga).
- According to Fujimaki-sensei, the nicest pun Izuki thought up is a follows: “Shingouki katte saikin shingo ukki uki! / I bought a traffic light, and I am excited about traffic lights lately!” 
|2nd years||Junpei Hyūga • Shun Izuki • Rinnosuke Mitobe • Shinji Koganei • Satoshi Tsuchida|
|1st years||Tetsuya Kuroko • Taiga Kagami • Kōki Furihata • Hiroshi Fukuda • Kōichi Kawahara|
|Other||Tetsuya #2 • Kagetora Aida • Alexandra Garcia • Kenji Takeda|
|Former players||Teppei Kiyoshi|