Recording tape cartridge configured to suppress damage to guide wall portions that are orthogonal to a loading direction

A recording tape cartridge comprising:

• a reel that includes a bottomed cylindrical hub around which a recording tape is wound and a reel gear that is configured to mesh with a drive gear provided at a drive device;
• a case that houses the reel;
• a brake member that is disposed inside the hub in a radial direction, that is moved in a direction of a rotation axis of the reel in conjunction with an operation for allowing the drive gear to mesh with the reel gear and an operation for releasing mesh between the drive gear and the reel gear, and that takes a rotation-locking release position at which the rotation of the reel is allowed and a rotation-locking position at which the rotation of the reel is prevented;
• a first protruding wall portion that protrudes from the brake member and that is disposed along a direction orthogonal to a loading direction in which the case is loaded into the drive device, and a second protruding wall portion and a third protruding wall portion that protrude from the brake member and that are disposed at regular intervals from the first protruding wall portion in a circumferential direction of the brake member, when seen in the direction of the rotation axis of the reel;
• and
• a set of two first guide wall portions that is formed at an inner surface of a top plate of the case in the direction orthogonal to the loading direction in which the case is loaded into the drive device and between which the first protruding wall portion is insertable, and a set of two second guide wall portions and a set of two third guide wall portions that are formed at the inner surface of the top plate of the case at regular intervals from the first guide wall portions in the circumferential direction, the second protruding wall portion being insertable between the second guide wall portions, and the third protruding wall portion being insertable between the third guide wall portions, when seen in the direction of the rotation axis of the reel,
• wherein in a case in which an interval between each first guide wall portion and the first protruding wall portion is denoted by α, each of an interval between each second guide wall portion and the second protruding wall portion and an interval between each third guide wall portion and the third protruding wall portion is denoted by β, and each of inclination angles of the second and third guide wall portions with respect to the direction orthogonal to the loading direction in which the case is loaded into the drive device, when seen in the direction of the rotation axis of the reel, is denoted by θ, “α>β/cos θ” is satisfied.