This was never explicitly said in the comic, but Master has raised Hana since birth. The timeline goes like this:
Danbi’s mom disappears.
Danbi and his half sister (same dad, different moms) move into the hive, as they’re too young to live independently.
Danbi’s sister discovers she’s pregnant with a dandelion child.
Hana is born; Danbi’s sister dies from the labor.
About 3-4 years after that, Danbi moves back to his old house in the village because he’s getting too old to live with a bunch of girls/women and no other male in the household.