A short groove (Koshi-hi)
Usually it suggests the sword of the buddha "Fudo-myo'o". Sometimes it can mean any buddha.
It is not a decoration, but is the most simple symbol of prayers. So it must appear on one side.




Chopsticks

 
Lotus Flower
It means a seat of Buddha.

It doesn't appear as it only. It must be a set for a Sanskrit letter.
 
Buddha "Dainichi-nyorai"
A Sanskrit letter of Dainichi-nyorai

 
Buddha "Amida-nyorai"
Some styles of a Sanskrit letter of Amida-nyorai
 
 
Buddha "Fudo-myo'o"
Sometimes this buddha appears on the blade as a set of Sanskrit letter and a short groove, both on one side or separate onto each side.
Sanskrit letters of Fudo-myo'o, constructed with several letters


A Sanskrit letter of Fudo-myo'o like Shintogo style.


Decorative style like Kanemitsu, 14th century


Buddha "Marishiten"
A Sanskrit letter of Marishiten


A decorative style of Marishiten

Buddha "Aizen-myo'o"
Sanskrit letters of Aizen-myo'o
 

 
Buddha "Bishamonten"
A Sanskrit letter of Bishamonten
  
 
An example of Bishamonten

On the obverse side, a Sanskrit letter of Bishamonten.
On the reverse side, a short groove with a narrow longer groove beside it. It suggests a figure of Bishamonten who stands with a long halberd.

Buddha "Shoten"

 
A Hebraic letter "Shin"

Hebraic letters are not found in old Japanese swords. This is made by request of a customer.
We think, the spirit to put it into the blade accords with the tradition of Japanese sword.