If you liked the H2O ~Footprints in the Sand~ anime, the Anime-Planet community thinks you'd like:
For Aizawa Yuuichi, returning to the town where he spent his childhood has been an unusual affair. Yuuichi, it seems, has forgotten his memories of the past, including encounters with several young ladies who would love nothing more than to see him again. As the days pass, flickers of the past began to surface, revealing more and more of the dark events that once came to be. As the reuniting continues, Yuuichi soon starts to realize that his past may be far more complex than he once believed it to be...
Memerioes coming out of nowhere, changing someone's life and influencing other people - this is mostly what those anime are like. Moreover, they are kind of harem - one boy to whom many girls are attached. So there is a possibility, that if you liked one, you might enjoy another :)
It's been seven years since Yuuichi Aizawa returned to the city he once lived in as a child. Though many things happened to Yuuichi in his past, he can only remember bits and pieces. His parents left Yuuichi in the care of Akiko once again, and this time, he will attend the same school as his cousin Nayuki. Many different girls appear before him, and some of them seem to know him from his past. Yuuichi must now recover his memories of the dark secrets that he erased from his heart, before he loses his precious ones.
Another guy going into a new place, but this time, there's an even more similar plot; the fact that both guys are looking for something to heal them; one for his memories, and one for his blindness.
Kanon has better animation compared to this H20, but that shouldn't stop you from watching this anime.
When Makoto saw Kotonoha on the train one day, he fell in love at first sight. Luckily, his classmate Sekai’s nosy personality ensures him an introduction to his crush, and soon the two begin to date. However, Kotonoha isn’t the only one with eyes for Makoto - a fact that any horny teenager would be delighted with. With endless temptations, lies and heartbreak at every turn, Makoto and Kotonoha’s relationship will soon be put to the ultimate test...
H20: Footprints in the Sand and Oretachi ni Tsubasa wa Nai revolve around a young man who goes through different psychological and supernatural battles while building his own harem. They both bring a little extra spice to the harem genre in the form of a psychological aspect.