Original video animation, abbreviated as OVA media (and sometimes as OAV, original animated video, by English-speakers, though it was mistaken for "Original Adult Video"), are animated films and series made specially for release in home-video formats. Basically, the media was initially dubbed "OAV" for " o riginal a nimated v ideo".
The OVA's are separate from the series, and are usually just a little bonus from the producers, however it should be noted that they are non-canonical and should be treated as such. I hope this can help.
ONA and OVA are completely different in terms of their target markets. An Original Net Animation (ONA) is an anime that is directly released onto the Internet (1) while an Original Video Animation (OVA) is an animated film or series made specially for release in home-video formats.
The image from the OVA doesn't follow the same pattern, and there's much less text in the image to draw any conclusions. It bears some very superficial resemblances to stylised kanji or early Chinese scripts but it could easily just be random shapes.
The series producers decided to move the more "spicy" manga chapters into the OVAs, and because of this, they are chronologically spread between the anime episodes. What should be a
Queen's Blade - Beautiful Warriors OVA Queen's Blade - Premium Visual Book OVA Vanquished Queens OVA Queen's Blade - Rebellion Queen's Blade - Grimoire (currently airing, alternative setting to Rurou No Senshi) If you check MyAnimeList, under the related section, you can see sequels, adaptations and alternative settings.
In the OVA Rurouni Kenshin : Seisouhen, there was a scene where Sanosuke and Kenshin met each other again after a few years. Sanosuke tossed Kenshin a grilled fish on a stick and Kenshin wasn't able to catch it showing that the disease had slowed his speed and reaction time severely.
In 2011, a side story OVA was released with the Bluray collection of the series, titled "The True Meaning of Bento" (Bento no Gokui). This side story has little to do with the main plot, so in principle it can probably go in a lot of places in the story.
The 1993 6 episode OVA starts at the middle of the 3rd plot line. The 2000 7 episode OVA presents the beginning of the 3rd plot line, up to where to pervious OVA starts. Both of these are are a bit of a relic, differ grately in animation style and production as a while and, well the first one just oozes early 90s anime style.
