As more people get using mobile phones, smartphone which is a new generation of mobile phone with computing capability earns world-wide reputation as new personal business assistant and entertainment equipment. This paper presents a synthetic character which acts as a user assistant and an entertainer in smartphone. It collects low-level information from various information sources available in smartphone, such as personal information, call log, and user input. Collected information is used for inferring high-level information with Bayesian network and determining agent’s goal. This character takes a behavior appropriate to current situation using behavior selection mechanism. The proposed agent is toward a framework for integrating reactive and deliberative behavior.