RECLECTIONS OVA SPOILER
Note Spoilers follow
Kenshin eventually becomes ravaged by an unknown disease that is much like leprosy (the writers have admitted there is no medical explanation for his condition). To share his pain, Kaoru convinces Kenshin to infect her with the disease through sexual intercourse. Kenshin then leaves to go assist in the First Sino-Japanese War (primarily over control of Korea) as he had promised the Meiji Government, not fighting and killing, but instead helping people.
After the war's end, Sanosuke discovers a very ill Kenshin sometime after he'd fallen overboard on a ship. Sanosuke arranges Kenshin's return to Tokyo by boat. Upon arriving, a bed ridden Kaoru, almost on instinct, gets up to walk outside the dojo on the cherry blossom path, seeing her husband struggling with each step to meet her.
The two finally meet, and Kenshin collapses into her arms as he clutches her to him. They end up beneath a cherry blossom tree, where Kaoru tells him that they will invite the others for a cherry blossom viewing, and continue to gather in the years to come. With the silence growing stronger, Kaoru realizes that Kenshin has died quietly in her arms. Upon brushing his hair off his left cheek, Kaoru notices Kenshin's scar has faded away, signifying an end to his life of pain and bloodshed and commencement to a life of peace. In the final scene before the credits, she holds his head in her arms and weeps.