Aa! Megami-sama! (TV), Rosario to Vampire Recommendations
There are both very in depth romantic comedies. The main character's (Keiichi and Aono) both meet these women by mistake. Although Ah! My Goddess tends more towards the romance aspect, while Rosario+Vampire is more for a comedic ecchi genre, they are both awesome romantic comedies that I suggest fans of the genre watch.