Hikaru Mitsushima was just an ordinary freshman, but she couldn't help developing a crush on a sophomore who shared her love for astronomy. However, her life changed in a dramatic way when she made a wish on a shooting star and merged with a supernatural being. This granted her the extraordinary ability to transform into a massive giant, and ignited a fierce desire within her to become a hero. With her newfound powers, Hikaru engages in exciting battles as a towering heroine, completely changing the trajectory of her life.