Kamasutra is a manga from 90's.
The plot:
In short, a ecchi Indiana Jones.
the art:
Character design is dated, but the scenery is amazing and pretty realistic.
Character are clichet and plain, but they are funny. I am not a big fan of pervet old man, but professor is so crazy funny.
The main guy Ryuu is the tipical virgin, clumsy guy, but he is likeable.
Prince, the vilain, is the wicked man.

What I like:
this manga is so non sense, but clichet plot hooks you, you wanna know what it will happen next ( it will be a lot of scenes) and action scenes as well. Not quite bright lecture, but it's funny and relaxing to read, you laugh and... I recommend if you wanna some non sense sexy manga.