The ending song of "Butterfly Sea" is called "Yesterday's Future". The song has a lively and passionate style, and the lyrics complement the plot.

"Concave and Concave World" is a 3D online animation produced by Qichuangshe. The first season of the animation was released on major video websites in a weekly update format on June 28, 2016, with 32 episodes in total.

Story Introduction

The God of Creation in the concave-convex world is a very arbitrary and casual god.

He created countless planets and people in the concave and convex world, and ruled them as he pleased without any rules. He made some planets rich and beautiful, made some barren and desolate, and allowed some people to enjoy freedom. Happiness makes some people bear heavy taxes and hard labor.

Creation God established seven divine envoys to carry out God’s will on his behalf. However, Creation God does not completely deny his people the opportunity. If anyone wants to change their destiny, they can achieve it. If you wish, then go and participate in the concave and convex contest.

Contestants will receive special abilities given by the competition system, and they will exercise and use their abilities to continuously fight through levels. If they win the final victory in the concave and convex competition, they will get everything and be given to you and the Seven Gods. The same power to rule the world on behalf of God.