Find a sturdy bench, coffee table, wooden box, or surface that, when you place your foot squarely on it, your knee is at about a 90-degree angle or larger.
Hold a dumbbell in each hand by your side.
Step up onto the surface with your right foot and lift your left knee forward and up.
Lower the left foot back to the ground, landing softly.
This counts as one rep.
Osaka does two sets of 10 reps on each side.
For an easier modification you can simply step up on top of the surface, hold for a few seconds, then return to the starting position.