Saneki made Yusai promise that he would never to relay the teachings to anyone, even the legal heir of the Hosokawa family, and that they were only to be taught to one descendent of the Sanjonishi family to prevent this knowledge left untold in the family.
「たとえ細川家の嫡男の一人たりといえども、ぜったいに他人には、伝授しないこと、三条西家に、もし相伝が断絶するようなことがあれば責任をもって伝え返すこと」等を誓わせ、古今伝授を行った。