Our research goal is to improve stylus operability by utilizing the human knowledge and skills applied when a user uses a pen. Such knowledge and skills include, for example, the way a person holds a pen to apply a generous amount of ink to draw a thick line with a brush pen. We propose a form of interaction, Finger Action, which uses input operations applying such knowledge and skills. Finger Action consists of five input operations: gripping, thumb tapping, index-finger tapping, thumb rubbing, and index-finger rubbing. In this paper, we describe Finger Action, a prototype pressure-sensitive stylus used to realize Finger Action, an application of Finger Action, and an evaluation of the practicality of Finger Action.