A tape cassette includes a housing and a tape. An indicator aperture is formed on a front surface of the housing. An arm portion of the housing is defined by a section of the front surface and a first wall. An opening extends through the housing in a first direction perpendicular to a top or bottom surface of the housing. The opening is defined by the first wall, a second wall and a connection portion. The connection portion connects upstream ends of the first wall and the second wall in a feed direction. A first surface is provided in the connection portion. The first surface is disposed between the top surface and the bottom surface in the first direction. The housing has a first indentation extending from the bottom surface to the first surface. The first surface is parallel to the top surface or the bottom surface.