He is managed by the talent agency Toho Entertainment.
In 2019, during Nishigaki's second-year in university, he was recommended by a friend to compete in the "Mister Keio Contest" and Nishigaki was able to win the grand prize.
[1] However, later on, Nishigaki became interested in the idea of possibly appearing on television and decided to take professional acting lessons as a trainee at an entertainment agency for a year, but unfortunately, he was unsuccessful in getting any roles.
[3] After Nishigaki was unable to land any roles and was about to refrain from pursuing his aspirations in acting, he was scouted by his current manager and he was signed with Toho Entertainment.
[2] In 2021, Nishigaki made his acting debut in the live-action television adaptation of the manga Captivated, by You.