A gourd island where ancient civilization and future technology coexist. Gulu, a cute little mermaid in distress, is rescued by a human boy, Fishball, and so begins their intertwined and interesting lives. A journey full of thrill, fantasy and joy is about to begin. Can the little mermaid escape from the traps? Can the little mermaid escape from all the traps? How will Fishball protect the juggling elves from the ocean?

After the outbreak of the War of Resistance Against Japan, the Japanese army has been advancing, killing and looting our compatriots, the people hated to the bone, but unfortunately, the lone army is weak and the invaders can not. The Japanese army advanced into the Central Plains, the vanguard came to the necessary fortress: Maijia Village.