In the Hero TV show, Karina is known as the Idol Superstar of the hero world. Her costume features crystal nails and guns that shoot freezing liquid. Additionally, she promotes Pepsi NEX, a zero calorie version of Pepsi available in Japan from Suntory. Initially, Karina doubts her role as a hero, stating that it was merely a means to an end for her singing aspirations. Kotetsu talks with her after one of her piano performances and encourages her to pursue what brings her joy.
Even though Kotetsu is a goof and does some pretty stupid things, she eventually develops feelings towards him. Even the sudden knowledge that he has a young daughter drove her into a state of shock. The sudden revelation of him not dying during the H-01 attack made her burst into tears and hug him. In the epilogue, it is shown that her love for him is serious enough to make her read a book about how to make a single father (Kotetsu) fall in love.