The Bugster Buckle was previously worn by Graphite in his default Bugster form. For unknown reasons, Kuroto Dan also has one, possibly the same one previously worn by Graphite. It is possible that the Bugster Buckle is tied to the Gashacon Bugvisor through one way or another, as seen when Kuroto confiscated the Bugvisor from Graphite, the Buckle was no longer present on Graphite's Bugster form.