Abstract: A video analyzing device is configured to acquire information related to a motion of a target object based on a video showing the motion. The video analyzing device includes circuitry. The circuitry is configured to perform a video displaying process of displaying the video on a display screen of a display device; a region specifying process of specifying a part of a range shown in the video as a determination region; and an information acquiring process of acquiring the information based on a change in the specified determination region. The region specifying process includes specifying the part as the determination region based on an operation by a user for selecting a range surrounding the target object from a still image. The still image is part of the video and includes the target object.