A tape cassette comprising: a cassette case that includes a top face, a bottom face, a front face, and a pair of side faces, the pair of side faces extending in a front-rear direction that is a direction orthogonal to the front face; a tape containment area that is an area, in the cassette case, in which a tape roll is accommodated, the tape roll being a wound tape that is a printing medium; a first wall portion that is a wall portion provided along a portion of an outer perimeter of the tape containment area, the first wall portion being configured to shape a feed path for the tape that extends from the tape roll, the first wall portion including a first edge portion that is an edge that faces a first surface of the tape, and the first surface being one surface of the tape; a guide portion that is provided downstream from the first wall portion on the feed path, the guide portion being configured to be in contact with the tape regardless of an amount of the tape of the tape roll accommodated in the tape containment area, the guide portion facing a second surface of the tape, and the second surface being the other surface of the tape; a second wall portion that is provided between the first wall portion and the guide portion, the second wall portion being configured to shape the feed path, and the second wall portion including a second edge portion that is an edge that faces the first surface of the tape; a third wall portion (503, 519) that is provided on an opposite side of the tape from the second wall portion, the third wall portion being configured to shape the feed path, and the third wall portion including a third edge portion that is an edge that faces the second surface of the tape; characterized by a fourth wall portion that is provided between the second wall portion and the guide portion, the fourth wall portion including a fourth edge portion that is an edge that faces the first surface of the tape, and the second edge portion being provided in a position along a straight line that connects the first edge portion and the fourth edge portion. a cassette case that includes a top face, a bottom face, a front face, and a pair of side faces, the pair of side faces extending in a front-rear direction that is a direction orthogonal to the front face; a tape containment area that is an area, in the cassette case, in which a tape roll is accommodated, the tape roll being a wound tape that is a printing medium; a first wall portion that is a wall portion provided along a portion of an outer perimeter of the tape containment area, the first wall portion being configured to shape a feed path for the tape that extends from the tape roll, the first wall portion including a first edge portion that is an edge that faces a first surface of the tape, and the first surface being one surface of the tape; a guide portion that is provided downstream from the first wall portion on the feed path, the guide portion being configured to be in contact with the tape regardless of an amount of the tape of the tape roll accommodated in the tape containment area, the guide portion facing a second surface of the tape, and the second surface being the other surface of the tape; a second wall portion that is provided between the first wall portion and the guide portion, the second wall portion being configured to shape the feed path, and the second wall portion including a second edge portion that is an edge that faces the first surface of the tape; a third wall portion (503, 519) that is provided on an opposite side of the tape from the second wall portion, the third wall portion being configured to shape the feed path, and the third wall portion including a third edge portion that is an edge that faces the second surface of the tape; characterized by a fourth wall portion that is provided between the second wall portion and the guide portion, the fourth wall portion including a fourth edge portion that is an edge that faces the first surface of the tape, and the second edge portion being provided in a position along a straight line that connects the first edge portion and the fourth edge portion.