3.547 out of 5 from 51 votes
Honoka Sawada is a lonely fourteen year-old girl who has no friends at school and spends her nights alone - that is, until one day she wakes up to find a fire-breathing baby named Mao in her bed! After meeting the mysterious principal of the Chibi Devil nursery, Honoka learns that Mao is in fact a demon baby, and she is now his surrogate mother. With only her anime-obsessed childhood friend Kyou and his hot-headed pal Shin to rely on, Honoka decides she can’t possibly look after a child and asks the principal to find a replacement parent. Now, until a substitue can be found, Honoka will have to spend the next month looking after Mao, but will she be able to cope, especially when a strange pair of teenagers are intent on taking Mao for themselves...
Ishiyama High is home to a whole host of delinquents, including Oga, a legendary badass who's downright devilish. One day Oga finds a man floating down a river, after which the man splits open to reveal a baby inside – but it’s no ordinary baby! The cute tot is actually Beelzebub, the future king of the demons! And as Oga is as mean as they come, Beelzebub latches on to its newfound 'father', much to the other demons' dismay. Now, in addition to battling rival gangs and becoming the strongest delinquent around, Oga must buy diapers, comfort and carry around an annoying baby who's more of a devil than he is!
Both manga are about a middle school girl who finds a baby and has to take care of it together with a boy around her age. However the baby isn't human (Mao-chan is a devil while Ruu-chan is an alien) and has magical/psychic powers so the heroine has to make sure that others won't find out about it.