Fanservice is found in many anime, in many forms. When it appears to be a major focus of the show, then it's safe to assume you're watching Ecchi. "Ecchi" (pronounced "EH-chee) is used by English-speaking anime fans to refer to soft-core pornographic or sexually suggestive anime and manga. This is entirely a western invention, as in Japanese, it is a catch-all term for all things sexual, not limited to porn and not really considered a "milder" term. The term "ecchi" in Japanese comes from the pronounciation of the letter "H" in English - "aitch" is rendered into Japanese syllabary as エッチ, which in turn is transliterated into the Roman alphabet as "ecchi". The letter "H" comes from the word "Hentai", but the term as currently used is not synonymous with Hentai. The line between Ecchi and Hentai can be hard to draw at times. However, one good rule of thumb is, if it was aired on Japanese public TV at all, it probably wasn't Hentai. Ecchi usually features Barbie Doll Anatomy, or avoids nudity with lingering Panty Shots. Hentai, on the other hand, will usually show full frontal nudity in some explicit form, and full, intimate sex scenes. At its mildest, Ecchi is closer in spirit to shows like Threes Company and Are You Being Served?, full of Double Entendres, big misunderstandings, and sexual farce. At its most explicit, it is still more in the realm of HBO Presents than Vivid Video. Another good way to distinguish the two are if there are any animated sex scenes. If so, you have left this genre entirely. To borrow an old saying, when it comes to sexual content, Ecchi is the sizzle; Hentai is the steak. Due to its dependency on fanservice and sex-orientated-humor: the focus is generally the females, which leaves the protagonist to be a stale, faceless camera to capture all of the escapades and shenanigans going around him. Possibly because sex is inherently funny, a large number of Ecchi series are comedies. Many start out as softer versions of actual hentai content (such as video games), while others may revert/graduate back to such if an OVA is released.