This is basically the point where the manga's first issue begins, and after a few minor storylines, the Shishio story arc begins.
This arc, in a nutshell, is where Kenshin's successor, Shishio Makoto, comes back to take over Japan. (After Kenshin retired the Hitokiri inside of him, the Ishin Shishi had to find a replacement for their best assassin. The man they chose was the cunning, razor-quick Shishio Makoto. However, they were unable to control him, and as such ordered his death. He survived, however, and ended up being horribly burned all over his body.)
This arc begins with the introduction of Saitou Hajime, another old ghost from Kenshin's past. He was the fourth captain of the ShinsenGumi during the Bakumatsu, and one of the Battousai's main adversaries.
In any case, Saitou is now working as a Police Officer for the government, and he is heading the investigation surrounding Shishio (read: it's his job to kill Makoto). Under orders, he goes to Kenshin to enlist his help, and after a brief fuss, Kenshin eventually agrees. They separate on the way to Kyoto, however, and on one of the lesser-populated areas of Kenshin's path, he meets Makimachi Misao.
Misao actually tries to rob him, but Kenshin being Kenshin, befriends her instead. They eventually end up travelling to Kyoto together, since Misao lives there and decides not to let him out of her sight.