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Shinshū Maru was a significant advance in amphibious warfare, having incorporated numerous innovative features, and as such she was shrouded in a veil of secrecy throughout her existence. She could carry 29 Daihatsu-class landing craft, 25 Shohatsu-class landing craft and four armoured gunboats, to be launched from a floodable well deck.
In addition, it was planned that Shinshū Maru should carry aircraft in a hangar within her voluminous superstructure. The aircraft would have been launched by two catapults to support amphibious assaults, but the catapults were removed before completion and the ship never carried any operational planes.