Genki Holiday Special: Appears after you have beaten the DLC campaign.
Number of instances: 3 (easy, medium, hard)
Easy -> Burns Hill ( Upper left corner of the map)
Medium -> Rosen Oaks ( Right side Middle of the map)
Hard -> Sunset Park (Right side lower section of map close to star island)
These will appear first as unknown GPS events on your screen. If you are having trouble locating them, turn your activities only on using your D-Pad.
This works the same as Genki M.O.M. except you are throwing Ginger Bread people, Christmas trees and Menorahs though rings using telekinesis. There are two rounds for each of the instances.
Some people are having troubles with this. I tried throwing people first, then trees and then Menorahs and that seemed to work. If you are missing a tree, go back to the first area and pick them up.
You just need to complete this, you do not need Gold medals to get the achievement. However, if you still are missing gold medals for normal Genki M.O.M., then these will count towards that medal total.
Edit: As pointed out by Park Diesel, if the game glitches on you during the hard challenge then dashboard. Start back up the challenge.
Throwing in order: people, trees, menorahs. He also suggests not moving your character around during the second half of the challenge, just use your right stick to aim, grab and fire.
Hope this helps everyone else out on getting this achievement.