The OVA Rurouni Kenshin: Reminiscence aired for four episodes between February 20 and September 22, 1999.
Despite Kenshin's reputation as the carefree ronin who goes wherever the wind blows, this OVA series reveals his troubled history. This OVA is very serious and does not have any humorous moments. Instead, it focuses on Kenshin's tragic love story and bloody history.
Given that each episode is 30 minutes long and there are four of them, the whole thing can be seen in just over two hours.
Disclaimer: The photo belongs to its rightful owner.