Gōshi possesses short black hair parted to the left, longer in the back, and distinctive red snake-like eyes with visible white between the iris and lower eyelid. He favors black clothing, often accessorized with necklaces or wristbands, and maintains a lean physique through training for vocal performance. His personality presents a rough, tsundere exterior; he frequently frowns and displays a temper, especially when frustrated. He openly dislikes non-musical idol activities and prefers working alone, often retreating to play guitar. Despite this standoffishness, he is deeply passionate about music, possessing absolute pitch and the ability to compose ad-lib. Fluent in English due to his American upbringing, which also influenced his mannerisms, he is stubborn and vocal about his opinions, sometimes disregarding others. Fundamentally kind and dedicated, he exhibits a strong work ethic once committed.

Within THRIVE, Gōshi frequently clashes with Yūta’s easygoing nature but remains protective of his teammates. He initially distrusted B-PROJECT A&R representative Tsubasa Sumisora, doubting her ability. Their shared passion for music fostered mutual respect, leading to relaxed discussions about audio equipment and new releases; he blushes when confronted with her genuine admiration or thanks. He shares a close bond with the Teramitsu twins, Yuduki and Haruhi, known as the "Returnee Trio" due to overseas experiences. They communicate in English, and the twins often persuade him to join activities with persistent requests or promises of treats. Gōshi acts as a caring senpai, driving them places or admonishing Haruhi for untidiness. In return, the twins express deep affection, with Haruhi cooking his favorite curry and cherishing a hand-me-down shirt.

His dynamic with Akane Fudo of KiLLER KiNG stems from their shared Bambi era history, where Akane was initially slated for THRIVE. Akane harbors an inferiority complex toward THRIVE, particularly Gōshi, viewing them as possessing "genius musical sense." Gōshi disapproves of rookies like the Ultras unit, perceiving them as arrogant and disrespectful to their label, Gandara Music. He struggles with group activities outside his unit. When temporarily staying with other B-PROJECT members due to teammates' illness, he felt uncomfortable with MooNs' accommodating hospitality and Kitakore's aristocratic environment. He finds Momotaro Onzai tolerable after initial communication issues but is irritated by Mikado Sekimura's comments about his temper.

Gōshi demonstrates gradual development in navigating group dynamics while maintaining his individuality. His dedication to music remains unwavering, but he learns to tolerate collaborative efforts and values evolving connections, particularly with Tsubasa and the Teramitsu twins. His background as a returnee and aversion to horror themes or ghost stories are recurring traits. His favorite foods are ramen and hamburgers, his hobby is reading American comics, he has hay fever, and he avoids sunscreen.