My Top Ten Harems

Raku’s attempts to find the owner of a pendant that he got from his first love. Unable to remember her face or name he believes the girl in question has they that will be able to open the pendent. The story will take you to answer the mystery of who is the past girl Raku fell in love with. while all pretending to be the fake lover of Chitoge due to unique circumstances.

currently has two seasons and the manga is already completed :)

When Ryuu Yamada entered high school, he wanted to turn over a new leaf and lead a productive school life. He chose to attend Suzaku High, where no one would know about his bad reputation. Unfortunately his quiet and normal life doesn't last long after Ryuu meets Shiraishi the cold beauty honor student. A misstep causes them both to tumble down the stairs, and end up kissing accidentally. To their surprise they discover that they can switch bodies with a kiss.

When the first year students are required to perform a summoning ritual, Louise's summoning results in yet another explosion. Everyone assumes that she is truly living up to her nickname "Louise the zero" but when the smoke clears, a boy named Saito Hiraga appears. He is now Louise's familiar, and is treated as a slave, forced to clean her clothes and be treated like a dog who eats and sleeps off the ground. his power seems far greater than it seems changing Louise for the better

Because of Kazumas brother (Ayumu) poor health, their parents thought it best for the family to move out from the city to a more rural environment. Kazuma and Ayumu are off to the Yorozuyo Inn where they’ll be staying until their parents can settle their work and other things back in the city and set up their new home. After realizing that they were taking a bus that would lead them to the opposite direction of the Inn they were left to wait at a bus station that would take an hour to come get them. As they were waiting for the bus a monkey ends up stealing Ayumu's hat. after chasing the monkey Kazuma ends up meeting a really cute girl.

Hiroki is an art student at Nadesico Academy (both a High school and University) who hopes to be an art teacher in the future. He is also the advisor to the high school arts club where his cousin, Elis, attends. While Elis is a painter like Hiroki, Hiroki seems to have given up on his dreams and no longer paints. Meanwhile, the high school hires a new PE teacher, Kikyo Kiri. On the first day, she bumps into Hiroki and is surprised to see for classmate and to her knowledge one-sided crush.

This anime doesn't really revolve around the harem itself but nevertheless is still categorized as a harem.
When the heroes are provided with resources and comrades to train with, Naofumi sets out with the only person willing to train alongside him. He is soon betrayed by her, however with false accusation of him taking advantage of her. He becomes hated by the people of Melromarc for something he didn't do. Hurt of the betrayal and the unfairness of his discrimation, Naofumi begins his journey of strengthening himself and his reputation. He realizes that it would be very hard to of a job being by himself, so he buys a demi-human slave on the verge of death named Raphtalia.

this anime actually isn't really considered as a Harem anime but I included this anime because most of the females in the series do end up falling love with him.

Kazuto Kirigaya, nicknamed "Kirito," is among the lucky few who get their hands on the first shipment of the game. He logs in to find himself, with ten-thousand others in the game world of Aincrad. The players soon realize they cannot log out; the game's creator has trapped them in his new world until they complete all one hundred levels of the game. They also eventually realize that dying in the game means death in the real life too. Just like with life there is no do over in this game.

Living under the same roof with the girl he has a crush on should be a dream for Shinichirou Nakagami, but the reality is closer to a nightmare. At school, Hiromi is bright, academically successful, athletic, and popular. But at home, Hiromi is a completely different person; she's cold and distant. he soon meets a strange girl named Isurugi Noe who suddenly takes an interest in Shinichirou.

when the decision is made to merge the elite Yuihime Girls' Private Academy and the coeducational Kagamidai Private Academy, rather than just bringing the Kagamidai boys into the Yuihime girls' school all at once, a plan is concocted in which a group of test males will be inserted into the Girls' Private Academy first. Shingo is one of the test students to enter the all maiden school and is surprised by some of the girls hostility of the boys. in hopes to get along with his new classmates he is encourage by his sister to just be himself. Knowing in time that the girls would soon realize Shingo charms and sincerity.

Hachiman Hikigaya, a student in Soubu High School, is a cynical loner due to his traumatic past experiences in his social life. This eventually led to him developing a twisted personality. He firmly believes that joyful youth is nothing but a farce, and everyone who says otherwise is just lying to themselves. He turns in an essay that criticizes this exact mentality of youths. Irritated by the submission, his homeroom teacher forces him to join the Volunteer Service Club—a club that assists students to solve their problems in life, hoping that helping other people would change his personality. He finds out that Yukino Yukinoshita, the most beautiful girl in school, is surprisingly the sole member of the club a fellow loner, albeit colder and smarter than Hikigaya. Their club soon expands when Yui joins them after being helped with her problem, and they begin to accept more requests.