Man, you can just feel the intensity of the final arc beginning. The pieces are pretty much set, now for the final climax.
Itto and Retsudō agree to the date and time of their next battle and hopefully their last. We'll see if they even end up fighting now that Retsudō is being summoned to the castle by the Shogun. At first Retsudō was curious as to why he was being summoned, but he later finds out what's going on. The Shogun's secretary, the guy that bit his tongue had told his daughter to tell Retsudō if he never makes it home. Now Retsudō knows something is up with the Yagyu letters and he'll be more prepared when he has to face the Shogun.
Retsudō also has the kunoichi call for the rest of the grass (ninjas) to come to Edo and be ready. Retsudō has a plan.
After Itto left Retsudō's home, he is spotted in town and now the police are trailing him.