Happy is a young resident of Dodeka Tree, consistently bullied and perceived as weak. Yearning for strength, he seeks training from his idol. This hope shatters when his idol prioritizes helping those in need over direct battles against villains. Happy's resulting disillusionment creates an opening exploited by the antagonist Baikinman, who unleashes chaos using a newly created gluttonous maggot creature named Gringa. Happy's journey involves grappling with his initial expectations of heroism versus the reality of compassionate action and confronting the vulnerability that malevolent forces exploited.