This paper describes the on-line handwritten character recognition method in an arbitrary place without the information of up and down moving of the pen lifting. This method can be applied to the character interface (aerial handwritten character recognition device) with which the user moves the hand in the air. To realize the system, we selected the gyro sensor for the aerial handwritten character recognition device. This device can detect the moving direction. The advantage of this device is able to be used anytime and anywhere like a pen. It is not necessary to preparer the table in order to detect absolute position. We developed the blackboard model recognition system that includes 2 types DP matching recognition programs. The system is able to recognize the Japanese hiragana characters in 84% accuracy.