Christina was a Japanese dance instructor who lived in Osaka during the 2010s. Christina acquired worldwide fame for the overseeing the success of many idols, although he rarely took the stage himself, and he only took on clients whom he saw potential in. In 2012, Akari Natsukawa introduced him to Haruka Sawamura, whom he agreed to instruct ahead of the Princess League finals, although he chose not to help Akari, seeing her dancing as too robotic and emotionless. After Mirei Park's death, he decided to help Haruka and Misa Yamaura materialize Park's wish: to hold a concert at the Tokyo Dome for Haruka's debut.