Also known as: 亀頭責め, 龟头责
A sex act in which mainly the head of the Penis is stimulated, the shaft is not touched or only for Holding.
This often takes the form of a Handjob where the palm is used to rub the head in circles, or a Cloth Glansjob where a taut piece of cloth is used to rub it back and forth. It can also be accomplished by performing Fellatio or Footjob on the head of the penis.
If there's any penetration involved, use Just The Tip instead.