I have hanatchi on v3 right now. I took perfect care of him as a baby and child, then I took OK care as a teen. I let the hearts empty a few times, he was overweight a bit a few times as a teen.
Well I had a teenager that was about 20lbs overweight and she turned into Hanatchi. Because she is a universal character she relies on care rather than skill points to determine what she will become.
My theory is, that if you take good care of a girl, but don't get her any skill points, with luck, she'll be a hanatchi. It happed to me with Angel the 1st (I've had 3 tamas named angel xD)
I had a Hanatchi from poor to bad care. I can't remember exactly because it was the third character I ever got. I think the skill points were fairly low.