Hentai Season...umm [insert number]?

I wanted to know for some time now is there any hentai out there that has actually been going on for so long that it get broken into seasons? Also in case your wondering the Fork I'm typing about I mean like Family guy, Simpsons, Naruto, Bleach, and etc. These shows been out for a while and least broken into five plus more seasons. So has there been a hentai series that done the same or at least close to?

Why yes. Although not 5 episodes per season. More like 2-3.

Examples:
-Oni Chichi
-Kateikyoushi no Onee-san
-Anejiru

So there are some that extends to seasons. Now that one hentai series caught my eye "Kateikyoushi no Onee-san", now I only watched two episodes. I didn't think there was more especially from "Anejiru" finally some closure about that cat(if there is). So about how many seasons has the three examples you given have?

1. Oni Chichi, Oni Chichi 2, Oni Chichi: Re-birth, and Oni Chichi: Re-born.
2. Kateikyoushi no Onee-san & Kateikyoushi no Onee-san 2: H no Hensachi Agechaimasu.
3. Anejiru & Anejiru 2.

I recommend the Stringendo & Accelerando series. Oh, and the Ikusa Otome Valkyrie series.

1. Accelerando, Stringendo: My Blow Jober, Stringendo & Accelerando: Ultimatum Sera, and Stretta.
2. Ikusa Otome Valkyrie, Ikusa Otome Valkyrie 2, Ikusa Otome Valkyrie G, and Ikusa Otome Valkyrie Shinsou.

Would the Mahou Shoujo Ai/Erena and all those count as well, or are they all independent?

I believe they're independent, but I'm not a hundred percent sure.

Oh yeah I totally forgot about "Stringendo & Accelerando" series. Also do these continuing series still have the same character, stuck with the same main character just different girls/boys that he/she bangs, or completely new characters same concept.

Kateikyoushi no Onee-san and Anejiru still have the same cast of characters except that in Anejiru 2 the Neko girl finally gets some.

As for Stringendo and Accelerando, they do focus on recurring characters alot, but they also give us new characters for the whole/remainder of the episode.

Alright another question. Is there some sort of channel in Japan, or anywhere, were they show like a t.v. series hentai show where it lasts like the traditional 20 minutes (plus commercials) and come out with a new episode each week? Maybe it can like an HBO show where the characters have sex for one episode and the next two episode is story driven to get a better connection with the characters. Then which of course bring back the bone-i-sode and repeat. Would anyone want something like this or is this just my fantasy, what you guys think.
Also what kind of genre and or type of porn would it be.