Rurouni Kenshin: Meiji Kenkaku Romantan

Synopsis

It is found in the notebook that the divine elixir may possibly cure any illness. It is also said that the Black Knights desire the divine elixir in order to acquire world domination. The Sanada Ninjas has issued a bargain to join forces with the Black Knights, to have ownership over Japan. The protagonists head to Suwa Shrine at Lake Suwa, the location of the divine elixir. They approach a priest to gives them information regarding the history of the shrine. The Sanada Ninjas attack the group, but retreat and go back to their base when they are bombarded by the Oniwabanshuu. The Black Knights tell the Sanada Ninja that they will make their move once the protagonists find the divine elixir.

(Source: Wikipedia)