At the end of last year Luna Muenster suffer a big lost. The planet where they train as a Warrior dissapeared due an evil force that taked over all the living beings and consumed them, the Planet Nexus sucumbs to "The Entity".
The times has passed, Luna and they friend escaped and keep going togheter. You cannot cry forever, you must get up and fight! You can't stop to fight, THAT'S WHY YOU'RE A WARRIOR...