The main conflict in The Secret of the Lovely Eyepatch (ラブリー眼帯の秘密〜 Raburii Gantai no Himitsu?) is between the Yagyu Jubei and Ryujoji schools. The rivalry was seemingly ended 300 years before the events of the series, when Yagyu Jubei defeated the Ryujoji school champion. Dying from his wounds, Jubei told his loyal companion Koinosuke to find someone with "plump, bouncy bon bons" and give her his eyepatch that contained a lifetime's worth of sword techniques. Unknowingly to Koinosuke, the Ryujoji clan plots their revenge.