Kugani-Udun was a private area for the king, queen, and the king’s mother. It was connected to the Seiden, Nike-Udun, and Kinju-Tsumesho on the second floor. The second floor of the building also had private quarters, a garden. On the first floor was the Saekimon passage (also known as Kurashin Ujo). It functioned as an exhibit space after restoration was completed and opened to the public in 2014.
This building was destroyed in the fire.