Rurouni Kenshin Tsukiohen

From Wikipedia.org:  

The OVA series, which features a number of historical characters, attempts to be more realistic and accurate than the TV series, which begins as a romantic comedy but evolves into a period drama. The OVA made use of live footage spliced with animation cells giving the series a different feel than straight animation. Both OVAs were re-released internationally in "Director's Cut" forms that spliced the separate "episodes" together into continuous movies, as well as adding some extra footage. The order of musical cues in both director's cut OVAs were significantly lessened and altered, although the tracks themselves were not altered or omitted.

The first OVA series, Samurai X: Trust and Samurai X: Betrayal, collectively known in Japan as Tsuiokuhen (追憶編, Recollection?) and later edited into a movie as Samurai X: Trust & Betrayal -Director's Cut, was set during the downfall of the Tokugawa shogunate and telling of Kenshin's childhood and teenhood. Only a few characters from the TV series appear in this OVA, namely Kenshin, Kenshin's master Hiko Seijuro (Seijuro Hiko in the English anime), and Saitō Hajime (Hajime Saito in the English anime), as well as a cameo by Makoto Shishio in silhouette at the end. The OVA mainly depicts the life of Kenshin as Battosai and his time with his first wife, Tomoe. Kenshin is nine years old at the beginning and eighteen years old at the end of the OVA.