Zero is a very stupid child.
As Zero's childhood sweetheart, Jin always needs to look back at the girl who is trying to follow him, in case the little girl is lost if he doesn't pay attention. He has always been a carefree character, and all the little delicacy he had was given to his little childhood sweetheart.
But despite this, there will always be times when things are thick and thin.
The little girl who had been following him suddenly disappeared without a trace.
Jin: "... Zero?"
Concept: Childhood sweethearts are the most embarrassing ones.