The existence of wireless and mobile technology has provided opportunities to support learning regardless of the physical learning space. Thus, usage of mobile terminals such as smart PDA (personal digital assistant) in a learning system is very common phenomenon. Mobile devices can communicate with wireless mobile terminal and realize the intelligence exchange with its surroundings. Based on this current trend and the need to realize learning in a more dynamic environment, a LOCH (Language Learning outside the Classroom) system named One Day Trip is developed to assist overseas students to learn Japanese in real life situations with the help of a PDA. This paper proposes a task assignment support to help the teacher to give learners appropriate tasks in the learning environment.