Himo is name of the traditional ties used to close the front of the haori (see photo). The ties can be replaced by a beaded strand of about 5-6" length that has hooks on either end to fasten the small loops sewn inside the haori to accommodate the woven himo, which is removable. The image is of a beaded himo on eBay.

I recently purchased two vintage summer-weight silk haori from Japan - they are a steal at $10 each. You can find them on eBay by searching vintage haori. I may string some beads to make himo for both of them, but note that for women, the himo is tied so that the front lapels of the haori close and the himo is not visible. So a beaded himo will serve as a "hidden treasure" if worn this way. In a similar concept, men's haori often have very plain exterior fabric, but gorgeous print or embroidered linings that are only seen by the wearer when donning or doffing the garment. A very Japanese detail!