Yuito Hoshina began his basketball journey playing streetball with friends before being scouted by Honmoku East High's head coach, Yūsaku Iijima. He joined the formal team, rising to become the starting small forward and ace. As a senior, he spearheaded Honmoku East's effort in the Kanagawa Inter-High Preliminary tournament; though the team failed to qualify for nationals, his standout performance earned him recognition as one of the tournament's top five players.

His playing style emphasized explosive offense, particularly dunking and two-point shots, skills noted to rival those of his primary rival, Kazuhiko Aikawa, whom he dreamed of defeating. While disliking defensive drills, he approached them seriously when necessary for victory. Personality-wise, he combined a naturally cocky attitude and occasional unseriousness with a hardworking dedication to basketball. He developed romantic feelings for Satomi Anzaki upon meeting her and confessed, but stepped back after she rejected his advances.

Following graduation and retirement from active play, Coach Iijima recommended him as Honmoku East's new coach. Encouraged by expressions of gratitude from members of Mizuho High's basketball team, Yuito accepted the assistant coach position, committing to mentoring the next generation.