Otherwise known as scrolling comments, danmaku comments (not to be confused with our actual danmaku tag) refer to the unique commenting system created by Niconico. Later also adapted by other sites such as AcFun and Bilibili (despite NND's owners owning the patent for it, due to a legal loophole).
Danmaku comments are displayed as floating text that scrolls over the video, from right to left. This leads to comments flooding the screen ala danmaku when users react to big moments. Users can customize the time that their comments appear, or they can make their comments stay on the top or bottom of the screen for 3 seconds.
