Naga Maru Gata (oval), Maru Mimi (rounded) border, Tetsu Muji 鉄無地 without pattern, Kogai and Kozuka Ana present.

• Material: Iron, smoky black finish
• Dimensions: 74 mm x 69.5 mm x 4.5 mm
• Weight: 134 g

Tetsu Muji 鉄無 is a solid tsuba without patterns, decoration, or relief.
This type of tsuba was produced by armor smiths, Katchushi 甲冑師, during the Muromachi period, a period of great wars. The important thing was to be able to quickly produce robust pieces without embellishments to arm the fighters.
The absence of relief will be appreciated by practitioners because friction with the surface will not cause lesions on the fingers. There will also be no related connotations or symbolism.

The term Muji 鉄無, 'without relief', can still refer to Mushin 無心, 'Without thought', a reduction of the Zen concept 'Mushin No Shin' 無心の心. This concept of emptiness refers to a mental state of emptiness leading to the 'instinctive', 'pure', 'ideal' gesture sought by the practitioner.