Hibaru Yotsurugi, the only biological heir to the Yotsurugi yakuza family, is caught in a power struggle with his adopted siblings over who will be the next boss. But when a meteorite crashes into Tokyo and people begin manifesting mysterious powers called Astros in the aftermath, their gang war becomes superpowered!

The chaos of the disaster splits the city into rival factions. Now Hibaru must use his newly granted Astro powers to protect his community from enemies—except some of those enemies are his own siblings, and they have their own plans to take over the Yotsurugi family!