Confusion is perpetuated because the size is the same: about 18mm or 3/4 inch in diameter. And with a perforation large enough for smooth passage of two cords. Sellers on ebay offer beads like these as ojime. And, sometimes, designers choose to lengthen their ojime necklaces with beads like these because their cost is low.

Adding to the confusion, 19th century Japanese farmers occasionally adapted foreign beads for functional usage. Many adaptations on inro can be seen in Chicago's Field Museum Collection. Museum protocol, for historical integrity, seldom allows alterations or repairs. When the date of museum acquisition is close to the time in which the objects were part of a Japanese gentleman's wardrobe, there is more information concerning how they were actually used. ~Whereas, at one time I would have been tempted to replace ojime adaptations by idealizing the ensemble.

The word "ojime," literally translated means: "slide closure" in Japanese. Functionally, the perforation requires a smooth edge for minimal abrasion of cord passage. As on most beads, examination of the hole is critical.

The way I learned it: The ojime bead should be made by a Japanese person for usage as a slide closure on a netsuke/inro ensemble. This definition conflicts with functional substitutes.