Let's just put it out of the way by stating that indeed, when the creators tried to ramp up the perversion factor, the anime got awful. There's nothing wrong with poking fun at society's rigid mores, but you cannot be clumsy and crude doing it if you want a good result.

Here's a representative screencap from the infamous episode when they went full retard. This is Hio-tan. She is sitting in the middle of Akihabara's main street. Fortunately, the vehiclar traffic was stopped as they do on Saturday.

Hio-tan and Fu-garu are cosplaying. All characters are known by their goofy handles in that anime. Kinda like Author, actually.

This is Sensei-chan. She is a mangaka and my favourite character (purely for being a bit more normal than the rest). I already spent several of her good screencaps, but there's more whence that came.

Here Sensei-chan is readying for a pantsu battle (spoiler: she's not actually trying to draw pantsu; her artistic abilities are good enough without the help of Master of Pantsu).

Sensei-chan is obsessed with her "joshiryoku", commonly translated as "Girl Power", but really meaning a measure of how ladylike one is. You can see the joshiryoku meter getting dangerously low in this screenshot.

You'd think that yukata would add +5 to joshiryoku, but actually no, if you don't know how to tie up your obi, it doesn't. Still, Sensei-chan is even cuter than usual when wearing it.

And finally, the best Sensei-chan screencap. What is happening here is that she noticed that the mugicha bottle is almost empty. So, since she's finishing the bottle anyway, she chose to chug straight, even though she's holding a cup that she prepared! This way she avoids washing the cup. At this point her joshiryoku is hitting negative values. This is how you develop a character, an excellent work by the creators.

Tsumorin's joshiryoku is enormous, the highest in this anime by far. Unfortunately, she's a drunkard. Stupid anime stereotypes!

Umio-kun and Kameko. Kameko is obviously a pun on "turtle", and I really suspect that the hat she's always wearing is her turtle shell. But this screencap shows her without the hat. It is the final episode, where she emerges from her shell. This is the other meaning of "charater development", also present.

G-woman (actually "Ji-man" in the original, after the Hoover's G-men, because she works for the government). She is the most visually appealing member of the cast, but alas... defective too.

UPDATE: As it turns out, "Kame-ko" is a pun on "Camera Girl", canonically. So much for my deductions... Development did actually happen though.