Out of the Pico trilogy, PicoxCoCoxChico is, by far, the best. While its plot and its characters are not quite as good as they were in the prequel Boku no Pico, this one is better at what it was meant to do: being a hentai animè.
I liked the characters because they always wore very sexy clothing. Their attire included classic maid outfits, incredibly short miniskirts, crop-tops and super tight T-shirts. WThe traps wore very sexy outfits. The underwear was the best part. It was what REALLY turned me on. While CoCo boasts tight-fitting panties underneath his frilly, transparent night gown, as does Pico, Chico tends to wear male briefs, or not wear underwear at all. Every thing these Shota wear, weather masculine or feminine, always looks hot on them.
However, the main thing I like about this anime was the sex scenes. Although the genitalia was pixeled over, these were some of the hottest sex-scenes I've ever seen. They contained many close-ups and various camera angles. There were many different sexual positions seen in this OVA. It involves oral sex, anal sex, hand-jobs and threesomes. Perfect for any perverted shotacon. While this not have a plot, it is still an amazingly sexy hentai.