It's more tangled but also more relaxed and enjoyable, a bit campus, a bit imaginary, a bit fairy tale, a bit science fiction.
It mainly talks about the heroine's search and growth in the shuttle between dreams and reality, and different time and space environments.
Once means never. Nothingness, meaning, cannot be repeated. How to learn, how to search, and how to grow?
How much does it cost to distinguish between love and like?
Is it the shuttle between reality and dreams, or the entanglement between past and present lives?
When things change and people change, I know what my heart really wants.
Once is never