Eiken OVA is an OVA adaptation of a not-so-popular manga, Eiken. For the most part, the story is weak and the characters are boring, but at least the setting's not bad.
Eiken takes place in a Zashono Academy, a huge institition comprising of elementary, junior high, and high schools. The main character is Densuke Mifune, who recently enrolled into the high school. Soon after he arrives, he gets forced into the mysterious Eiken club, comprised of mainly teenaged girls with extremely large breasts. With that being said, this OVA is DEFINATELY not for children under 17; with the situations the characters get themselves into, it's practically soft-core porn. I won't go into detail, but the anime covers almost every single perverted act possible without transforming into a full blown porn film.
This might sound like heaven for teenage boys, and admittedly, it is; however, once the novelty wears off, the only thing that's left is a very boring and repetitive OVA. The characters are boring; they're really one-sided and have no depth. The same thing could be said with the story, or lack thereof; it's just one perverted situation after another. There's a vague storyline behind all of it, but it's totally irrelevent. Basically, one of the girls in the Eiken club is having a birthday party, and the entire school is throwing her a party.
In the end, I would NOT recommend this OVA at all. There's really nothing else to be said, aside from DON'T WATCH THIS OVA.