Kyouran Kazoku Nikki

Thousands of years ago the God of destruction, Enka, died saying thats its child would destroy the world.Thousands of years later the potential children of Enka are found (some human, some not) and take part in the Peaceful Family Operation in order to discover who the true child of Enka is and stop them from destroying the world by teaching them the importance of family love.
The novels depict the not-so-normal life of a "family" that includes a catgirl "mother," a lion "son," a living land-combat android weapon "son," a jellyfish-like otherworldly "daughter," and a hapless 27-year-old military officer as their "father." This motley "family" was assembled as part of the Imperial Japanese Anti-Paranormal Phenomena Section's Special Operations Forces to save Earth in 2063.
(Source: ANN)