Unusual and funny Hentai Manga recommendations??

[nihonbashi]

Hi!
If you ever came across some unusual and/or funny hentai manga titles, please recommend me some !!
(only translated to English please)

For example:
Kigenzen 10000 Nen no Ota - The Otaku in 10,000 B.C. - where the MC gets sent back in (you guessed it) 10,000 BC and gets to do some cavewomen from various tribes and "invents" the various sex positions and kinky plays :D

Thanks!