Chitose Hitotose was orphaned at a young age and is now in high school. He yearns for a family and a place to belong, but his long years of independence and isolation are setting his feet on a dangerous path. What is the solution that his teachers conceive? He needs a mother... but it's not just one, but five "Mamas!" Absolutely no one can discover that his teachers live under his roof, and he has to hide the fact from everyone, from the class president to the principal! With their maternal instincts in overdrive and mysterious pasts, can Chitose learn the lesson of happiness?
Haré and his mother live peacefully in the jungle, until one day the boy is overtaken by a omnipotent shadow. Later, he awakens to find Guu, a strange girl with even stranger abilities - notably, the ability to switch from a cute, lovable Guu, to a menacing delinquent who eats everything. Now Haré must live with Guu, and lead a normal life, despite her oddities.
Once upon a time, a creature named Enka tried to destroy everything on Earth. It was eventually slain by humans; but before dying Enka proclaimed that one day its child would return to the planet, spreading fear and despair throughout all humanity. Now, thousands of years later, DNA tests have identified six 'children of Enka'. Only one of them is dangerous, but nobody knows which one (and killing them all would be mean!) Instead, 'Operation Cozy Family' is born! Normal human Ouka Midarezaki is forced into marrying Kyouka, one of the children of Enka; and together they play the roles of 'father' and 'mother' for the other children. But will family bonding and love really be enough to prevent the destruction of the planet?
Kei Kusanagi is a shy teenage boy with no romantic experience whatsoever... until he finds out that his hot new teacher is actually an alien! In order to conceal her identity, the two are forced into a pretend marriage... but is it really a pretense, or are they actually falling in love?
Fifteen-year-old Tsukune Aono is average in every way; he has no hobbies, less-than-stellar grades and he's even flunked his high school entrance exam. His parents have managed to enroll him in a school, but it's no ordinary school! Tsukune will be attending the Youkai Academy, a place where monsters learn how to co-exist with humans! As the werewolves, vampires, witches and other monsters are required to retain their human forms, Tsukune - the lone human - is able to avoid their bloodthirsty gazes. However, he quickly attracts the attention of a number of devilish beauties including the vampire Moka, a busty succubus and even a young witch! It seems Tsukune's average life isn't so average anymore!
Minato Sahashi was living a normal life; he had just failed his college entrance exam for a second year in a row, and lived a quiet life in a single's apartment. That is, until the busty Musubi fell from the sky on top of him! She is a Sekirei, one of 108 that are destined to fight each other until only one remains; and he or she will ascend to heaven with his or her chosen one known as an Ashikabi. Minato soon finds himself in the embrace of Musubi, becoming her Ashibaki - but his life will only become more complicated. Musubi isn't the last to claim Minato as her Ashibaki, and what's worse, plenty of other Sekirei and opponents stand in his way!
Happy Lesson and Sekirei both contain a male protagonist who ends up living together with several females competing for his attention. Wacky hijinks ensue. Each series contains a healthy dose of romance and comedy. Sekirei also contains some mild nudity.
Assuming you have no problems with the nudity and you liked Happy Lesson, I would recommend giving Sekirei a try. Conversly, if you enjoyed Sekirei, give Happy Lesson a try.