Michisio Nagasumi is your average 14-year old schoolboy, who was
dragged along by his parents to go on a summer vacation on the remote
inland mountain beach of Seto. When he and his parents went to the
beach, bad luck strikes when he got washed away on the sea, leaving him
helpless on the fact that he is about to drown, when suddenly, while on
the brink of death, a girl with a tail (in Nagasumi's blurred sight)
saves him.

However, bad luck seems to be Nagasumi's brother-in-fate, when he
discovers that the girl who saved him, named Seto San, is actually a
mermaid. Catch is, San is the only daughter of Seto Gozabura, boss of
the Seto Group, a Yakuza-like organization that has a grimly rule: Any
human who discovers a mermaid/mermen must be killed, or the said
mermaid/mermen would be killed instead. The only way for Nagasumi and
San to escape this rule, is to get married (even if Gozabura objects,
and only wishes to kill him instead)!

Facing dire (and stupendous) consequences, Nagasumi starts to embrace
his eccentric new life, as he slowly adapts himself to the world of
Mermaids and Mermen, as well as to learn more about them, especially
his newly-wed wife, San-chan, while balancing them with normal Human
life.

http://www.instantz.net/anime/Seto_no_Hanayome.html
http://www.zomganime.com/anime/seto-no-hanayome/

http://en.wikipedia.org/wiki/Seto_no_Hanayome


Twi's Review:
First off let me say this is DAMN funny, you will laugh so much you'll hit the ground with a smile on your face. The entire family is hilarious from the shark who constantly tries to eat the boy, the sharp and smooth, manly swordsman Masa. The typical romances are there, all with comedic results and a large number quirks like the battles over the lunar and san fans in episode 8 to luna's papa(The Terminator) walking in on the boy with luna and going terminator on his a** and trying to off him by dumping him in tokyo bay and went Judgement day on him. Practically everyone tries to off the boy and well it's just hilarious. I give this series a 9/10 in comedy, but some parts are disturbing. Watch it!