An adolescent with the ability to control a looming war-golem becomes entangled in the Experts of Justice's fight against the infamous group Big Fire.

Eccentric prince and wannabe adventurer Muscat Tyler embarks on a secret tour of his vast empire, accompanied by two of the galaxy’s strongest fighters: Ruu, a powerful young elf, and K.K., a mech-clad rogue. A crash-landing puts the newly formed group on the trail of a historic treasure on a strange planet, testing their abilities — and their patience for each other.

中学女生Nayuta在回家路上救了一个和母亲一起被外星人追杀的小男孩Kiro。因为好奇Nayuta戴着Kiro头上戴着的形状类似戒指的金属头饰去学校上学，被假扮成老师的外星人盯住。外星人在烧毁Nayuta的家致使其父母身亡后抓走了Kiro。Nayuta在同样头上带金属环的龙太郎带领下和同伴们会合，开始了在苏子引导下的反抗绿色恶心外星人的战斗...