Iron tanto tsuba decorated with carvings, inlay and lacquer.
On the front of the tsuba there are two distinctive decorations. The one at the top is onigawara, a roof ornament depicting a head of the demon. They are most often seen on Buddhist temples. At the bottom there is a tile with tomoe. This are more often used to decorate Shinto shrines but we can also see them on Buddhist ones.
On the front there is also Paulownia Go-San Mon. In the past used by Toyotomi Clan and now by government of Japan.
On the back side of the tsuba there is a chrysanthemum, emblem of Japanese Imperial court.
At the bottom of the back side there are three Kanji letters. At this point I am not able to read all three of them. First one seems to be "天" (Heaven) and second one "王" (king). Those two Kanji are used to write "Four Heavenly Kings" who are Buddhist goods. However this phrase is written with 4 kanji not 3.
Other options are:
1. ten-jin-chi: heaven-man-earth
2. Tennoji: name of the temple in Tokyo or district in Osaka.
Size: 57 mm x 42 mm x 4-5 mm