A tape cassette that can be mounted in and removed from a tape printer that is provided with a head holder that has a printing head, the tape cassette comprising: a box-shaped cassette case that includes a top case and a bottom case, the top case having a top wall and the bottom case having a bottom wall and a bottom outside wall (303, 304) that is an outside wall (303, 304) extending vertically upward from an edge of the bottom wall; a tape that is contained in the cassette case; a head insertion portion that is a space extending through the cassette case in the up-down direction and into which the head holder is to be inserted; an arm portion that has a first wall portion and a second wall portion, and that is adapted to guide the tape along a feed path between the first wall portion and the second wall portion to an exit, the first wall portion being a portion of the bottom outside wall (303, 304) and the second wall portion being provided between the first wall portion and the head insertion portion and being a wall extending vertically upward from the bottom wall; a front face indicator portion that is provided in the first wall portion and that indicates a type of the tape; and a width direction restraining portion (381B, 383) that is provided in the second wall portion and that is adapted to restrain a movement of the tape in a width direction, wherein the front face indicator portion includes a plurality of indicator portions that are disposed in a pattern that is in accordance with the type of the tape, each of the plurality of indicator portions is one of a non-pressing portion and a pressing portion, and the width direction restraining portion (381B, 383) is provided in a position that is adjacent to the front face indicator portion and that is visible from in front of the first wall portion. a box-shaped cassette case that includes a top case and a bottom case, the top case having a top wall and the bottom case having a bottom wall and a bottom outside wall (303, 304) that is an outside wall (303, 304) extending vertically upward from an edge of the bottom wall; a tape that is contained in the cassette case; a head insertion portion that is a space extending through the cassette case in the up-down direction and into which the head holder is to be inserted; an arm portion that has a first wall portion and a second wall portion, and that is adapted to guide the tape along a feed path between the first wall portion and the second wall portion to an exit, the first wall portion being a portion of the bottom outside wall (303, 304) and the second wall portion being provided between the first wall portion and the head insertion portion and being a wall extending vertically upward from the bottom wall; a front face indicator portion that is provided in the first wall portion and that indicates a type of the tape; and a width direction restraining portion (381B, 383) that is provided in the second wall portion and that is adapted to restrain a movement of the tape in a width direction, wherein the front face indicator portion includes a plurality of indicator portions that are disposed in a pattern that is in accordance with the type of the tape, each of the plurality of indicator portions is one of a non-pressing portion and a pressing portion, and the width direction restraining portion (381B, 383) is provided in a position that is adjacent to the front face indicator portion and that is visible from in front of the first wall portion.