Dream? Meng Hui? Meng Xi
FYI
Supplement:
Oh, I finally understand after reading LZ's supplementary pictures.
This turned out to be the title of a song by Takamura Shinji.
If LZ is studying Japanese, I can communicate with you as follows:
Adjectives in Japanese and conjunctions in ancient Chinese are all in the form of adjectives stem+き.
Speaking of figure, it is used to modify body language. For example, the Japanese translation of the Blue Danube by Strauss is full of the charm of ancient Chinese: beautiful, green, beautiful, beautiful, beautiful, beautiful, beautiful, beautiful, beautiful, beautiful, beautiful, beautiful, beautiful, beautiful, beautiful, beautiful, beautiful, beautiful, beautiful, beautiful.
In fact, the question you asked is an adjective, which means uncertainty and impermanence. Shinji Tanimura once wrote a song title with a taste of ancient China, which became 儚き; And as a song title, sometimes you don't have to follow the strictness of grammar, so it is treated as a noun here. Of course, the latter "は" is used as an auxiliary word.
In addition, the Chinese translation in your picture is not accurate enough in some places, please pay attention.
The above is for reference _