The comedy story follows the title character, who is regarded by himself and others as the best hit man in Japan. He goes by the motto, If I have an assignment, I will kill anything. However, his killing assignments have expanded to include everything from summer vacation homework to housekeeping. The hit man never fails to kill the target. Though he does not aim to, he also never misses the laughter. (Source: ANN)

Vampires are known to have many weaknesses that balance out their incredible power, but the vampire lord Draluc happens to be weak to pretty much anything. The vampire hunter Ronald receives a job to infiltrate the castle of the so-called Invincible Progenitor and rescue a woman's son from the monster within. But upon arriving, he is dumbfounded to discover that the vampire quickly turns to ash by something as trivial as a clap of his hands! Moreover, the child he was sent to save had merely wandered in to play the vampire lord's video games while he slept! In a disastrous turn of events, Draluc's castle is destroyed, and the fragile vampire decides to move in with the hunter who has only just defeated him. Ronald, Draluc, and the vampire's pet armadillo John form quite the eccentric team as they are forced to work together while fending off Ronald's violent editor, the lesser vampires plaguing the city, and even their fellow vampire hunters.

Tiara, a princess from the kingdom of Waleland, travels to the city of Mamkestell to attend a prestigious academy for those who practice magic like herself. After passing a test to prove her eligibility, Tiara reunites with her childhood friend Rosetta, who is also a student there. She then joins and meets Rosetta's group: the athletic Lavie, the reliable Ashley, and the bookish Lynette—all of whom Tiara quickly befriends. In this institution, students are placed into one of three ranks based on their test score: group Noir being the highest, followed by Rouge and Lapis. Tiara's group is ranked Lapis, and if that was not enough, those who fail while ranked Lapis face expulsion. Realizing their dire situation, Tiara urges everyone to start taking their activities more seriously. On top of this, Tiara has one more purpose for excelling at the academy: to become more like her elder sister, who is a very skilled singer. However, to reach the stage that she desires, she will have to overcome many challenges, along with her companions, as she continues her magical journey.

Yuuta Segawa has just started his freshman year of university. One day, his sister Yuri, who raised him after their parents died, asks him to take care of her daughters Hina, Sora and Miu while she and her husband go overseas on a business trip. Yuuta grudgingly accepts, but tragedy strikes when their plane goes missing and all passengers are presumed dead. In an effort to prevent the three girls from being split up, Yuuta goes against their family and takes them in, just as his sister took him in when he had no one else. Now the four find themselves in a new and peculiar situation: Yuuta must learn how to balance his new responsibilities—as the newest member of the Street Observation Research Society, a club for people watching, and also as a father figure—while Sora, Miu, and Hina come to terms with the loss of their parents.