Misugi Jun emerged as a Japanese football prodigy during elementary school, captaining the Musashi team while secretly battling a severe congenital heart condition that drastically limited his playing time and posed life-threatening risks if overexerted. Only his girlfriend, Yayoi Aoba, and his coach knew this truth. His early career featured a pivotal full-match performance against Nankatsu in the national semifinals, facing Tsubasa Ozora. Despite leading Musashi and delivering a stellar display, they lost 5-4. This effort nearly caused his collapse but cemented his determination to play. After a two-year middle school rehabilitation, he returned under a strict 30-minute per match restriction. In the Tokyo prefecture final against Toho, he collapsed after exceeding his limit yet still assisted a goal with a header. His condition necessitated a dual role as player and assistant coach for the Japan Junior Youth team, where his tactical insights proved vital, such as advising positional changes for Matsuyama. Acting as a super substitute in the International Junior Youth tournament, he contributed against Argentina and France but missed the final due to health. Following three high school years focused solely on recovery, he fully overcame his heart condition and secured a place on the Japan Youth team. Originally an offensive midfielder influenced by Johan Cruyff, he adapted to become a libero modeled after Baresi to serve the team's needs. He scored a crucial equalizer against Thailand in the Asian World Youth preliminaries and demonstrated exceptional field vision, notably comprehending and supporting Tsubasa’s Skydive Shot tactic against Mexico. Defensive partner Matsuyama and goalkeeper Wakabayashi acknowledged his reliability. Professionally, he joined Bellmare Hiratsuka before transferring to FC Tokyo in the J1 League, primarily playing right midfielder. A draw against Matsuyama's Consadole Sapporo ended with mutual respect for their skills. Selected for the Japanese Olympic team, he formed part of the "three Ms" alongside Misaki and Matsuyama, entrusted by Coach Kira to maintain team balance during Asian qualifiers. His calm judgment and performances were instrumental in Japan’s qualification. At the Madrid Olympics, his health issues resurfaced dramatically; he collapsed after blocking Schneider’s Fire Shot against Germany. Following an out-of-body experience and CPR from Tsubasa, he regained consciousness, convinced officials to let him continue by promising withdrawal if symptoms returned, and persevered into extra time. This injury benched him for the subsequent Spain match, where he offered defensive advice against key threats. His personality reflects strong will, kindness, cleverness, and selflessness. His medical knowledge enabled him to assist others, saving Mikami and treating Wakabayashi’s injuries. He maintains a long-term relationship with Yayoi Aoba, who anticipates a marriage proposal, though health concerns remain an obstacle. His tactical intelligence allows him to analyze opposing formations and influence play even off-field. His techniques include the Drive Shot and Overhead Block. Video game depictions feature moves like the Sky Rocket Volley (a high-powered jumping volley), Slice Shot (a horizontally spinning shot), and Magnificent Dribble. Gameplay skills mirror his adaptability and health limits: Glass Ace (boosting stats for the first 30 minutes before sharp decline) and Meister (enhancing stats based on team-high attributes). Throughout his journey, he balanced football with medical studies, inspired by Sócrates, evolving from a physically constrained prodigy to an Olympic-level player. His resilience and tactical brilliance solidified his role as a cornerstone of Japan’s defense and midfield across tournaments and professional leagues.