How to attach a string to a sword
FIG. 1

The center is A, where the string is folded in half. Check the balance of the sword and tie it at a suitable place.

This is a zoomed-in version of Figure 1. tying it once is fine, but tying it twice will give it a more luxurious look.

FIG. 4

After passing the sword through your hand, tie the other end in the same way.
Intertwine the strings on both sides with the horizontal string of B and tie a straight knot. Be careful not to tie it vertically.

Finally, tie a decorative knot in the shape of a C. For more information, please see here.
If this is difficult, you can also tie a bow.
難しければ、蝶結びでも大丈夫です。

The center is A, where the string is folded in half. Check the balance of the sword and tie it at a suitable place.

This is a zoomed-in version of Figure 1. tying it once is fine, but tying it twice will give it a more luxurious look.

FIG. 4

After passing the sword through your hand, tie the other end in the same way.
Intertwine the strings on both sides with the horizontal string of B and tie a straight knot. Be careful not to tie it vertically.

Finally, tie a decorative knot in the shape of a C. For more information, please see here.
If this is difficult, you can also tie a bow.
難しければ、蝶結びでも大丈夫です。