在宁静的小村庄里，一种怪病正在慢慢吞噬着村民们的生命。作为全村唯一能够拔出勇者之剑的青年义彦，去往未知的远方寻找灵药成为了他义不容辞的责任。灵药很快就被义彦找到了，可是故事并没有结束。佛祖现身赋予了义彦十分艰巨的任务——前往魔王的根据地，打败魔王。

女刺客阿紫，法师美列布和战士团丈接连加入了讨伐魔王的队伍。一路上，勇士们披荆斩棘奋勇杀敌，遵循着佛祖的指令收集着力量强大的道具，为最终之战做着积极的准备。而现在魔王近在眼前，面对它的强大，这四个渺小的人类真的能够获胜吗？

為人善良又單純的年輕人義彥，因為一些原因而被「邀請之劍」選為勇者。為了找到可以拯救受疾病所苦的村人們所需的草藥與為了草藥踏上旅程卻行蹤不明的父親光彥，義彥也踏上了旅程。旅行途中遇到了團藏、阿紫、梅列布三人加入成為同伴，而繼續旅行。不久之後，義彥發現了父親和草藥，正當大家以為旅程要結束時，佛祖突然出現並告訴他們，疾病發生的原因是因為魔王出現所造成，也因此讓義彥和同伴們踏上打倒魔王的旅行。

The story is set in an ancient time, when the whole country was covered in thick forests. A mysterious plague breaks out, resulting in countless deaths. A pure young man named Yoshihiko becomes chosen as a hero, and he sets out on a journey in order to save a village. He has two goals – to bring back the legendary plant that can cure the plague, and to rescue his father Teruhiko who left to find the plant but never returned.

작은 마을 '카보이' 출신의 순수하지만 어리버리한 청년 요시히코가 용사로 간택되어 역병을 치료하는 약초를 가지러 모험을 떠나는 것으로 시작해 마왕으로부터 세상을 구하는 장엄한(?) 활극...을 가장한 개그물.