- Shoulder tap (Yonkyō) is also the name of an aikido move.
A shoulder tap is an act in which a minor asks an adult to purchase alcohol for him or her. Typically, the minor will walk around a convenience store and solicit help from a passing adult stranger. This is also commonly known as a "Hey Mister".
A Los Angeles Police Department survey indicated that almost half of minors who attempt to acquire alcohol use this method. Such communities use sting operations to deter adult assistance and promote awareness of the legal consequences of helping minors obtain alcohol.
In 2001, a Mothers Against Drunk Driving (MADD) chapter conducted a small unscientific study in Massachusetts, in which teens stood in front of 15 stores and asked 100 adults apparently over the age of 21 to buy them alcohol. Eighty-three of the 100 adults refused and 17 agreed.