Devoted Servant Naosuke

Naosuke, a servant of Okajima Yasoemon, devoted himself to his master. One day, his master Okajima Yasoemon, lost his face in front of people. It was a revenge by Oono, a karo (minister) who lost his chance to earn money by selling a fake antique to the lord. Okajima told the lord it was fake. Okajima endured Oono's humiliation. But, his servant Naosuke, could not. But what could he do? Oono is superior of his master. Naosuke would not hesitate to lay down his life for his master. But killing Oono would ruin his master. He wanted to clear his master's disgrace. What to do?