Seikon no Qwaser II

Gigantic tits, plethora of fanservice and story that actually lore-wise depends on these massive mammaries. 

Both are sequels with significantly less ideas than their first season's had. Both end inconclusively and unsatisfactory. Both go for much less overall straight narrative and just linger on borderline episodic comedy. 

They both have the same spirit for good fights and also a very good ecchi 

Both of them have erotic scene, both of them, have lesbian or pseudo-lesbian interation. 

So when I heard Seikon no Qwaser uses "sucking on breast for milk gives strength" as a plot device which was a ridiculous idea, Astarotte no Omocha! introduced "drinking semen to gain immortality and beauty" We're all going to hell for watching this sort of shows....