We are developing techniques to count pedestrians using inexpensive pyroelectric infrared sensors. We have already proposed a method to detect numbers and directions of people walking through in a fixed direction or an opposite direction and confirmed its feasibility by various experiments. We consider techniques to count people walking through a one-person open doorway where they walk in various directions around it. A method using one sensor with a wide detection area and another using multi-sensors having a small detection area respectively are proposed. Some preliminary experimental results are also shown.