40 years ago, three mysterious seeds fell on Earth, unleashing numerous monsters. Chosen beings who fight against monsters. Those who made the heroic spirits of this world manifest their power through weapons or protection were called heroes. Min Jae-ha, who wanted to become a hero, went all the way to the front lines, but was unable to do so, and has given up his hopes and dreams of becoming a hero and works at That’s Real Company. Then one day, Min Jae-ha, who was investigating a mineral dungeon for company work, steps on a mysterious stone tablet, and Min Jae-ha, who dreamed of signing a contract with a heroic spirit, is granted a tremendous heroic spirit. But… “How many times must I have to tell you before you understand? I am alive!” “To be exact, you’re neither dead nor alive!” “What on earth can you do in my stomach?” Why did this tremendous heroic spirit settle in Min Jae-ha’s stomach rather than in the form of a weapon or divine protection? “Look up to me, and I will teach you martial arts.”