If you liked the Bakemonogatari anime, the Anime-Planet community thinks you'd like:
Ataru is one of the most desperate womanizers alive, and a man whose life is about to become complicated. When aliens invade, he discovers he has been chosen at random to be mankind’s defender, and must play a game of tag with the beautiful alien princess Lum to decide the fate of the planet! After chasing her with all of his crafty techniques, Ataru finally wins, but his victory also means he must marry the princess herself! Now, with strange alien visitors and a jealous wife to handle, Ataru still manages to keep an eye on his ultimate goal: having his own harem!
These are two of my favorite harem comedies. One is a classic and one modern, but both had excellent animation for their time. Comedy and ecchi that stays fresh should appeal to fans of either series.
Michiru has an unusual ability: she can see a dark ring around a person's neck that signifies their time to die. However, she suppressed her powers once she "saw" the deaths of her parents – until now. After accidentally seeing rings around the necks of two boys in her school, it seems that Michiru's powers are back for good. The two are zombies who are working for the secret loan office known as Zombie-Loan, and they need Michiru's help to find other zombies – those with dark black rings around their necks. Though Michiru initially refuses, due to a series of events it seems she has no choice but to comply...