BAKA.. An insult that casts a shadow on the function and contents of the subject's mind.. the word quite literally means fool. One could also say, o-baka or great fool. 

KAMI.. An expression for Supreme Being (God), which in Shinto, can also be used to describe lesser supernatural beings and spirits inhabiting the natural universe (see also SHINTO). When speaking of a particular god or God, it would be proper to say, kami-sama. Kami can be translated many different ways depending on the context, for example, kamikaze means "holy wind". 

ONI.. A fierce horned demon somewhat akin to the ogre found in Western mythology. Oni have the power to transform into the human female form in order to mask their true identity. he word "oni" is sometimes speculated to be derived from on, the on'yomi reading of a character (隠) meaning to hide or conceal, as oni were originally invisible spirits or gods which caused disasters, disease, and other unpleasant things. These nebulous beings could also take on a variety of forms to deceive (and often devour) humans. Thus a Chinese character (鬼) meaning "ghost" came to be used for these formless creatures.

OTAKU.. This word can have a very negative meaning depending on the context in which it is used. In Japanese society its usage is widely understood to mean someone who is an anti-social maniac. But in the International anime community the word has evolved into a slang reference meaning obsessed fan. Serious devotees of anime and manga call themselves otaku. 

GENKO – black fox, usually seen as a good omen

KITSUNE – (also Shakko) - fox, a general term for a fox regardless of the circumstance normally used for ‘good’ and ‘evil’ foxes alike (Also Coyote, Raven, Loki, Prometheus, Brer Rabbit, Anansi, Seth (Egypt), Eris, Hephaestos, Hermes, Odysseus, Sisyphus (Greece), Papa Legba, Ti Malice, Baron Samedi, Asmodeus, Jacob, Lilith, Nasreddin (Islam)

Sugoi. [f/m], Sugë. [m], Hampa-ja nai. [m] - Awesome - more - http://www.intercom.net/user/logan1/jap.htm

Ketsu-no ana-no chïsai-yarö! [f/m] - your hoop-hole is small! (or You're narrow minded!)

http://www.behindthename.com/nmc/jap.php