The underworld is composed of nine upside-down giant stars, which are called "Star Tower and Nine Abyss". The starlight is the source of all things, and the human race brings the starlight into the body for practice. In ancient times, there were people with "star bones" who were born to be in harmony with the stars, and they were unique. However, the protagonist's star bones were incomplete and he was regarded as a mortal body. The Star-devouring Monster Clan feeds on star-devouring stars and is at odds with other clans.
