My personal favorite Tenchi Muyo! is my recommendation to watch if you liked Happy Lesson. Both are a comedy/romance anime with 1 guy surrounded by numerous females in one way or another attracted to him. This series will make you laugh and blush at the same time. While Tenchi Muyo! adds a more fantasy like approach to it, they will both fullfil your hunger for romance and comedy. Hope you enjoy them as much as I did!