I've had both of them; they're not difficult to get. You can get either by treating the teen this way:
Constantly keep only one hunger heart filled; it may go to 0, but be sure to feet it soon after it beeps. Never give it a time out, but always praise it. Always play the dance game when it's unhappy (or give it a snack, but don't make it overweight), but you can play the jump game a few times if you wish. This technique has worked for me and many other people.
I believe Hanatchi appears in odd generations and Robotchi/Androtchi in even.