Sae Itoshi

A promising young player who is being watched by soccer clubs around the world as a midfielder. He has been selected as one of the new generation's top 11 players globally. He is the real brother of Rin Itoshi. His skills and talent as a player are of a very high level, incorporating advanced techniques and tactics into every play. Although he is a midfielder, his scoring ability is on par with or better than that of a professional forward, and he excels at counter dribbling, swiftly bypassing opponents with their movements and gestures. According to Kiyoshi, his soccer embodies the essence of "beautifully destroying" the game.

He generally has a proud and daring personality and behavior, and he was disappointed with the current state of Japanese soccer, which lacks forwards who can keep up with him. However, during his return to Japan due to an expired passport, he learned about the "Blue Prison Project" and began to take some interest in Japanese soccer. While he maintains a haughty attitude, he is not without the capacity to engage with others, responding to their conversations and demands to some extent if he recognizes them as worthy. According to him, he has no interest in anything other than soccer.

After the "Aptitude Test (Tryout)" during the third selection phase, he temporarily joined the U-20 Japan national team under the condition that he could heavily utilize Ryusei Shido from Blue Prison as his partner, and confronted the Blue Prison Eleven head-on. In the match against the Blue Prison selection team, he scored the first goal with a vertical downward spinning shot from just before the goal line. Initially, he seemed evenly matched with his younger brother Rin, but eventually outpaced him, declaring, "As long as you're my brother, you can't surpass me," and demonstrated the difference in their abilities as players competing globally. Although he created scoring opportunities in the first half, the U-20 Japan national team ended the first half trailing by one point.

He openly states that he does not recognize anyone as a forward if they have less scoring ability than himself, demanding that forwards score from the chances he creates. Therefore, he has great chemistry with Shido, who specializes in scoring in front of the goal, and they exhibit strong offensive power when in a FLOW state. Towards the end of the game, feeling the opponent's latent abilities and will to win, he finally showed his true effort, repeatedly putting the Blue Lock Eleven in difficult situations. However, in the final phase, after losing a one-on-one with Rin, Kiyoshi scored the winning goal, resulting in a defeat for the U-20 Japan national team. Shido, while making various excuses, promised to exchange contact information. Afterwards, he approached Rin, reconsidering his disappointment in Japanese soccer, and realized that someone like Kiyoshi might change Japanese soccer, and that there is still hope for change in Japan.

Following the U-20 Japan national team match, the media treated him as if he were a war criminal, but he simply stated, "The result is as you see it." His original position was as a forward, chasing the dream of being "the world's best striker," but after going abroad and learning about the world, realizing that there were better forwards than himself, he switched his dream to becoming "the world's best midfielder," which led to a rift and eventual fallout with Rin, who had looked up to him.