Naegi Castle"Tenshu"(keep)

The keep of Naegi Castle was built on two huge rocks and had three layers. The basement of the keep was called "Tenshu-en-no-shita (Space under the floor)". The size was 4 m x 5 m (13.1x 16.4 ft) including the board frame, and it was on the corner of the southwest side of the rock.

The 1st floor of the keep was provided with "Tama-gura (storage for bullets)". The floor area of the building was 6 m x 6 m (approx.19.7 x 19.7ft).