4-4 point low approach, high extension, hoshi
is three spaces away, so is a likely invasion later in the game. Aside from local responses, normally a, immediately seeking compensation in the corner is possible.
Another followup is , which secures Black's corner and threatens to invade at a. is frequent when White wants to respond, or she can first play a forcing move attaching to .
Black should play or have an extension around or beyond the midpoint of the side. Any closer and the 3-3 invasion will render this formation inefficiently cramped. If there is no extension, White is bound to attack at b.