This is a term coined to identify things like jiggling breasts, cleavage shots, panty shots, bra shots, closeup shots of women's breast, legs, butt, etc., and mild nudity all for the purposes of "servicing" the audience and having no relevance to the plot or characters of a series. The term has a second meaning covering things like massive action sequences, explosions, fights, etc., but it mostly refers to the first meaning.
Self-explanatory. In addition to having a romance, there should be humor too, often directly tied to the romance story.
Love Hina,
Aa! Megami-sama! OVA,
Chobits, and TONS more titles all fall under this genre.
