The Best Harem Manga of All Time

A high school student named Issei Hyoudou discovers he's been reincarnated as a devil after being attacked by a fallen angel, and his new life revolves around serving a high-ranking devil named Rias Gremory. As part of the Gremory family's group of devils, Issei must balance his daily high school life while combating supernatural threats and dealing with a growing harem of girls who are drawn to him. Over time, Issei's inherent powers grow stronger, attracting the attention of both friend and foe, forcing him to confront the rivalries and alliances among the mythological beings in his world.

In a world where mythical creatures have been integrated into human society, a man named Kimihito Kurusu finds himself hosting a variety of monster girls as part of an exchange program meant to foster understanding between species. Navigating the cultural differences, Kimihito helps these girls adjust to human society while also unintentionally becoming the object of their affections. Meanwhile, government operatives investigate Kimihito's increasingly chaotic household and monitor potential threats posed by extremists opposed to interspecies relations.

Arata Kasuga discovers that he's a mage after inadvertently using his magic to save his town from a mysterious Breakdown Phenomenon, and enrolls at a magical academy called Royal Biblia Academy to learn how to control his newfound abilities. As he befriends and battles the seven most talented female students known as Trinity Seven, Arata uncovers the secrets behind the magical world and the truth about the catastrophic event that destroyed his town. Throughout his journey, Arata encounters various challenges and sinister forces seeking to exploit his power for their own nefarious purposes, forcing him to reluctantly rely on his new friends and allies.

When a zombie apocalypse engulfs the world, high school student Takashi Komuro bands together with a group of fellow students and the school nurse to survive the carnage and uncover the truth behind the outbreak. As they make their way through the ravaged city, they must not only fight off the undead hordes but also contend with the dangers posed by other desperate survivors. Along the way, personal tensions and romantic entanglements threaten to unravel the fragile bond that holds the group together as they search for a safe haven in a world gone mad.

Minato Sahashi, a hapless young man, becomes involved in a high-stakes supernatural competition called the Sekirei Plan when he encounters and bonds with a mysterious girl with incredible powers called Musubi. As a participant in the plan, Minato must gather a team of Sekirei – otherworldly beings who gain power through forming contracts with humans – and battle against other teams to determine the ultimate victor. Throughout the contest, Minato and his growing harem of Sekirei must navigate dangerous alliances, confront powerful enemies, and unlock the secrets of their own pasts.

When human teenager Tsukune Aono mistakenly enrolls at Youkai Academy, a boarding school for monsters, he must conceal his true identity while navigating the challenges of life alongside his newfound supernatural classmates. Embraced by a group of female monsters, including a vampire named Moka Akashiya, Tsukune learns about the complexities of monster-human relations and the struggles they face in a world divided. As Tsukune's relationships with his classmates deepen, he is drawn into conflicts with dangerous adversaries seeking to maintain the status quo or exploit the young monsters' unique abilities.