It was the first North Korean film to win an international film award at the 18th Karlovy Vary International Film Festival in 1972 and remained the only one until the 1980s.

https://en.wikipedia.org/wiki/The_Flower_Girl#Reception

There was big, wholly fictional accounts of Kim's life from the commies of North Korea. They had him being a successful military and communist figure early on and coming from a different family than the one he really originated in. This play he wrote in 1930 bit might be and sounds real make believe. It was just about Japanese occupation of Korea which started in ,1910. Or did they just merely mean he co-wrote it? Probably the latter. He and someone else are credited as writers. But the deadly regime would probably support the idea that he did write it in 1930 should the public have misunderstood.