While visiting his hometown, junior high school student Michishio Nagasumi's life was changed forever when he nearly drowned. Though he was saved by a mermaid named San, there’s a catch -- her family is part of a merfolk mafia, and they abide by a strict rule: If a mermaid is discovered by a man, either he or the mermaid must die. That is, unless the man marries into the family! Faced with such a decision, Nagasumi can only oblige their customs and become a "happy" newlywed. Now, with a new school year around the corner, Nagasumi must find a way to deal with his new bride, keep her true nature a secret, and most importantly, escape inevitable death at the hands of San's over-protective father’s gang!
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?
An unassuming guy gets into a strange situation, crazy things happen, he gets forcibly married to a half-animal girl, some more crazy things happen, there's a jellyfish, and somehow everyone deals with all this crazyness and somehow no one laughs at just how funny it all is.
In present day Japan, the life of a school girl is never dull. The easily-bored Konata never finds time to study because of her otaku habits, which frustrates hard-working Kagami to no end. On the other hand, laid-back Tsukasa always manages to go with the flow, while Miyuki is concerned with keeping her status as resident know-it-all. Join these four girls as they muse and meander their way through everyday events such as eating chocolate cones, doing homework, gaming, and trips to the beach galore.
Takasu Ayako can handle anything; duels with foreign powers and assassination attempts don’t faze her. But can she handle falling in love? Fellow students at the prestigious school for Beatrice users are shocked to hear that their "Angel of Death" Ayako, who has never even shown a smile before, has fallen in love at first sight with the diminutive freshman Yoshimura Mamoru. Mamoru must decide how to respond to the sudden confession of love, the resulting fascination of his fellow students, and the dangers of being near Ayako. Will his own powers ever measure up?
Plots of Seto no Hanayome and Mamoru-kun have next to nothing in common, but the style of crazy humor is similar. If you liked one of those anime for the jokes, than you'll probably going to enjoy the other one as well.