Yuusuke was just a normal kid going to high school. Then one day, the cute and behaloed Noelle fell, quite literally, into his life, naked as a baby and every bit as innocent. Before he can even fathom what's just happened, Yuusuke is inducted into a rather odd family of otherworldly beings. Papa is a Frankenstein monster with a taste for calisthenics. Mama is a gorgeous lady with a penchant for "round objects" -- really! The eldest sister, Sara, is literally invisible; the brother, Gabriel, is a teenage vampire with an attitude problem; and the youngest sister, Ruka, loves inventing things. There's a disapproving Grandma, who's a witch to the nth degree, and her vulture familiar. All Yuusuke wanted was for the beautiful Natsumi to even notice his attention, but now he has an angel-in-training to follow him wherever he goes. And Noelle, too, has a guide on her path to being an angel, the mysterious Michael.

Sasahara Natsuki is a poor bounty hunter in a world where monsters and humans live together. Most of her cases involve monsters infringing upon the rights of humans, who are protected by law from their generally more powerful neighbors. Being half-human and half cat-beast, Natsuki straddles the two societies and tries to understand and respect both while enforcing the law. She is assisted by a werewolf named Batanen who is afraid to admit he loves her; another werewolf named Tommy; and a Kyubi fox demon named Sakura who has her own plans--which include eating Natsuki to complete her her nine tails and thereby her magical powers.

Amawa Hibiki is a young man just out of college, with an education to be an athletics teacher. He's been having a hard time finding a job since he graduated, so all his money has gone towards living expenses. When his landlady demands his first payment to live in her living establishment upfront, he heads to the local middle school to get hired as a teacher. However, the principal refuses to hire him without hesitation. She will not hire men as teachers and makes it clear that she hates all men, saying they put no love into their passions and work. Amawa does not give up and with the help of his landlady, he crossdresses as a woman without a second thought, and gets hired, so he can earn money and also prove the principal wrong. Now, he has to keep his real gender a secret, and avoid strange situations, including the affections of his students (from both genders).

The skilled craftsman Kuroda created artificial humans called Hybrid Child—creatures who are neither machines nor dolls, but rather a reflection of the love shown to them. While they can feel human emotions and have their own consciousness, they are not real humans and require love to grow. Kotarou Izumi is the young heir to the noble Izumi family, so it is frowned upon when he brings an abandoned Hybrid Child he found in the garbage into their household. His family even attempts to throw away Hazuki—Kotarou's name for the Hybrid Child—multiple times when he is not paying attention. But through overcoming these obstacles, their love and the bond connecting them grow stronger. However, ten years pass before a horrifying realization dawns on them: a Hybrid Child might not have an endless life span. Hybrid Child is a collection of three short love stories, depicting the relationship between the artificial humans and their owners.