Auxiliary tape cassette provided with case having guide surface around which printing tape is wrapped to form spiral portion

An auxiliary tape cassette comprising:

• a roll configured of an auxiliary tape wound about a winding axis, the auxiliary tape being used for printing on a printing tape that is conveyed;
• and
• a case housing the roll and having:
• a discharge port for discharging the printing tape from inside the case to outside the case in a discharging direction;
• and
• a guide surface for guiding toward the discharge port the printing tape supplied from outside the case, the guide surface being defined on an inner surface or an outer surface of the case,
• wherein the printing tape is wrapped around the guide surface to form a spiral portion whose angle of rotation about a central axis of the spiral portion is greater than or equal to 180 degrees, the central axis being parallel to the winding axis of the roll, and
• wherein the guide surface includes a curved surface for guiding at least a portion of the spiral portion on an upstream side of the discharge port in the discharging direction of the printing tape.