Yu Maoyi, who has always lived in the third dimension, knew that there was a lot of time and space because her father was an astronomer. Because of her rebellion, she always wanted to escape from the third dimension. And because she originally came from a royal family in the second dimension, Yu Maoyi's father had no choice but to use the cracks in time and space to send Mao Yi back to the "border" of her original life.
It was a transition where there was a distinction between "master and servant", because it was invaded by the dark tribe.
Mao Yi must follow his guardian Quan Yinnian and the king's guardian Mo Xi on the road to restoring the light of the country.
The heroine Tsubasa has a cold personality, but she falls in love with the innocent Kukai.
There are also many past connections with the next year and Mo Xi.
Everything begins and ends at that "border".