Shougo Mikadono's father has just passed away, and now he must become the head of Mikadono Group, his father's company. After completing the training to take over, there is just one other stipulation he must adhere to: he will need to find a girl he loves at his new school and marry her by the time he graduates high school. Shougo transfers to Miryuin Private Academy, and it seems like he has many girls to choose from, such as Konoe Suruma, the class representative as well as his first new friend; Miyabi Kannagi, a standoffish but kind girl; Rinka Kunitachi, the student council vice president; Mei Sagara, who runs a cafe and dresses like a witch; and Mana Tendou, the student council president. However, there is a complication: one of them is his long-lost half sister, and he has no idea which one, so how can he become romantically involved with any of them? [Written by MAL Rewrite]

After losing his mother, 14-year-old Taro journeys to Tokyo to live with his grandfather. But he gets the biggest surprise when he discovers that his grandfather's home is a huge mansion with hundreds of beautiful maids ready to serve him. Making matters worse (at least for Taro, but not for our viewing) is that not only does he inherit the Hanaukyo mansion, he gets the services of all of the maids 24 hours a day, 7 days a week.

One year ago, a UFO containing 150 aliens crash-landed off the shores of Kasai. Because no one could fix their ship, the Japanese Government decided to bestow upon them the designation "DearS" and make them into Japanese citizens, teaching them the language, customs, and culture of Japan. However, in order for them to become more familiar with human society, a home-stay program has been enacted to allow them to mingle with other humans. One misty morning, a truck carrying a capsule that housed one of these aliens ends up dropping it into the riverbank, releasing her from her confinement. She is eventually found by a high school student named Takeya Ikuhara, who saves her from being hit by a truck and takes pity on her, despite being extremely distrustful of their race and wanting nothing to do with them. Upon being named Ren, she imprints upon him as her "Master" and serves as his personal "Slave," leaving him with a "DearS" who wants to remain with him no matter what and bringing his ordinary, alien-free days to an end.

Two years have passed since the CCG's raid on Anteiku. Although the atmosphere in Tokyo has changed drastically due to the increased influence of the CCG, ghouls continue to pose a problem as they have begun taking caution, especially the terrorist organization Aogiri Tree, who acknowledge the CCG's growing threat to their existence. The creation of a special team, known as the Quinx Squad, may provide the CCG with the push they need to exterminate Tokyo's unwanted residents. As humans who have undergone surgery in order to make use of the special abilities of ghouls, they participate in operations to eradicate the dangerous creatures. The leader of this group, Haise Sasaki, is a half-ghoul, half-human who has been trained by famed special class investigator, Kishou Arima. However, there's more to this young man than meets the eye, as unknown memories claw at his mind, slowly reminding him of the person he used to be. [Written by MAL Rewrite]