That is a gag item to insert into the anus.

Chamberlain Yanagisawa Yoshiyasu

Eh

Is this true, Yoshi!?

Yoshiyasu would have Tsunenobu draw his portrait in his later years

Yoshiyasu was also the person who valued Tsunenobu's talent and interceded on his behalf before the shogun

Yoshiyasu-sama, nice!

Sticking foreign objects into their anus is something people of sin do

Dogs, who are superior, will do no such thing