it's an old ecchi, borderline H anime. It puts characters into some erotic situations, and has explicit sexual scenes without actually showing any body parts. Visuals are boring, but probably average for the time it was made. The characters have nothing more than they all want to have the seggs with the main protagonist. The main girls who want the protagonists D are two lolis who aren't blood related to him, but are still his sisters. There's also a school teacher who has big boobas, a first year with big boobas (who I think doesn't actually want the protagonists D, she's just there for diversity of boob sizes), and a very very young loli who is very sexual, relatively.
overall I enjoyed it, I just enjoyed the situations they found themselves in. There was a weird part near the end about sexualizing body odor, licking sweat, licking armpits, and bellybuttons, which is a major pet peeve of mine, so be warned. Places to watch this are plentiful with a quick Google search.