B-gata H-kei, Nazo no Kanojo X Recommendations
Young people make the same kinds of discoveries throughout. B Gata H Kei manages to be simultaneously more perverted and less disgusting, but then, it has a distinct shortage of spit sucking.
These two anime are very similar. Both have two virgin couples who are trying to understand each other and at the same time fall in love with each other. These two anime are also both ecchi, drama, and romance.
They both have some ecchi stuff and Urabe and Tsubaki were vigins same as in B Gata H Kei.
In both series the male and female leads involuntarily get dropped into a girlfriend/boyfriend relationship. They are reluctant at first, but they slowly embrace their connection. In both series, the leads never been in a relationship or close to anyone, so they stumble to discover the mechanics of how a true relationship/love works, discover each others' and their own bodies and feelings through some very awkward, sweet and slightly ecchi moments.
B Gata H Kei focuses more on corporeal love and it's overall theme is ecchi/pervy slapstick comedy. Nazo no Kanojo X uses drool as a main plot device, so that might turn some more squeamish