Yubizumo (Finger Sumo)

Two players interlock the four fingers of one hand together, leaving both thumbs free and upright.

On a starting count, each player tries to pin the opponent's thumb down using their own thumb.

A pin counts once a thumb is held flat under the opponent's thumb for a full second or two.

Players can dodge and feint with quick thumb movements to avoid being trapped while looking for an opening.

Play best of three or five rounds, switching which hand is used between matches to keep it fair.