This gate was built after TSUTSUI MON Gate was transferred from MASAKI Castle and is designed for surprise attack on the rear of the enemies who are trying to intrude through TSUTSUI MON Gate. The gate and Hidden gate Turret from the side of TSUTSUI MON Gate, and in spite of the small scale the large boards and wood make a bold structure. This gate with its lookout points and windows is reminiscent of the original Matsuyama Castle.