Lesson 507 is the 507th chapter of the Gintama series.
On a Harusame spaceship, Abuto and his subordinates examined the head of the Shogun, with the latter confirming that it was truly the Shogun's head. Nevertheless, Abuto did not really believe that and voiced his suspicion of Hattori to him.
While so, in the forest, the Shogun had shown up among the lines of the shinobi, ordering them to attack Fujibayashi. Fujibayashi was about to hit the Shogun when he was stopped by Momochi. It was revealed that it was Hattori who hid the Shogun in Iga a month ago with the help of Momochi. She then criticized Fujibayashi for conspiring with the Harusame to get a hold of Iga, but he had thrown kunais at her head before she could finish. Suddenly, her head turned into a cannon and went off at Fujibayashi, thus killing him. In fact, the true Momochi was the maid pushing the wheelchair, not the person sitting on it.
In Iga, Momochi told the Yorozuya about the sides of the village (one of which was Fujibayashi, and Momochi was the other.) She also talked about the fact that the dead Shogun was, in fact, just a body double, completely unawared that the Shogun was overhearing. Everyone sat in silence, while Ayame thought of Hattori. Suddenly, she stood up and ran outside, presumably looking for him. Momochi asked everyone not to let anyone know of the Shogun's survival, believing that no one would die if they kept the secret safe. Gintoki disagreed with her and looked outside, seeing spacecrafts of the Kiheitai and the Harusame coming towards them.
Characters in order of appearance