Japanese nickname

I am thinking of naming myself �…�_ (Suijin) meaning "water God". Is that name suitable for a woman?

A nickname does not have to be suitable in anyone else's eyes, it is after all only a nickname :)
If you like it then that is all that matters.

http://en.wikipedia.org/wiki/Suijin
If you think dragon, surpent, snake, eer and kappa are suitable for a woman, there is no problem.

If you plan on introducing yourself as Suijin in Japan, expect people to be very taken aback. It would be quite odd, whether for a man or a woman. Can you imagine if a Japanese person introduced him/herself to you as "Water god" in English? Pretty much the same thing.

Seems like it's not appropriate then. "Suijin" is a yugioh character so I never thought that far.

I think I am just going to call myself "Mikue".

Beware of naming yourself anything from anime, manga or trading cards, as they have little connection with reality or everyday life in Japan. If you would happily take a nickname (aren't nicknames usually given to you by other people anyway?) from an American cartoon or comic, then by all means, go ahead.

There is nothing wrong with the name Jenny though, if that is your real name, and Japanese people will have no problems pronouncing it.

If you give yourself a Japanese name, expect to be constantly asked "Why?"

you would choose nickname what is more close to your own name. your name is JENNY right? then find japanese girls name with starting JE...
my real name is ANU so i use AYU in japan. as you can see, only one letter changed.
( if you wonder my real name, it's finnish name, i'm from finland )

Radical idea: just call yourself "Jenny".

There are no Japanese names starting with the sound "Je.." as that sound isn't used in Japanese. The only girl's names I can think of that even start with a J are Jun or Junko, and perhaps Juri, which is a more modern name.

Think about the anime "Claymore". There are some great nicknames in it! I don't know how to say all of them in Japanese.
Bishou no Teresa=Teresa of the Faint Smile
Genien no Miria=Phantom Miria
Windcutter Flora, Flash Sword Irene or even Rippling Ophelia!
Also in Naruto there is Sabaku no Gaara [Gaara of the Desert.].

Tsunade, those names might be fine for posting on internet forums, but you can't introduce yourself to a Japanese person using one of those names in real life! Think about the situation where the name might be used a bit more.

Would you introduce yourself to someone in an English speaking country saying "Hi, I'm Teresa of the faint smile"? Can you imagine the reaction?