I don't exactly know how the name Kinso came to my mind but when I played Devil Survivor Overclocked for 3DS and saw the protagonist...yea :D
I thought Kinso would fit him perfectly and there is my name from :D

ErinacchiLove is a username I use almost everywhere. My name in Japanese is Erina, and Erinacchi is like a pet name of it. I added "love" to the end at some point just for the hell of it and it kinda stuck ever since.

I was playing an MMORPG not long ago, and I saw this cute character named Blue Screen @o@ I then aspired to use that name wherever I made a new account ever since~

I'm kinda surprised the name isn't taken in this forums though

Well my name is T

Chigüire is the name of an animal. This name is only used in the country I come from. This animal is very famous in my homeland.

It is commonly known as capybara 

Then I added an X at the end just because.
More on capybara here

ashkie_mami

ashkie (it just cope up into my mind and that name also is my usser name in all my accounts in any games)
mami ( at mami sasazaki because she's my favorite scandal band member, and i feel that someday i will have a picture with her so i decided to name it)

i both like panda and dinosaurs so i combined it.Pandadinawsawrs!! .cool.

i both like panda and dinosaurs so i combined it.Pandadinawsawrs!! .cool.

My username was from a pretension I've made 2 years ago...  
It was because I tried to text my old cellphone number(since I've dropped my old sim card when I was still 1st year). Then I texted it saying "can you be my text mate?". I thought no one would reply to it, but when I got home the day after that I've received so many messages. I got scared when she replied and asked me what my name is      . Since "Jenny" is the name that came first into my mind I just said it's Jen(though my name is not really Jen). Then she replied to me that we also have the same name(but as I've said my name is not really Jen). After that, she told me not to text that number ever again.  

I even still have those messages she sended to me 
BTW, my real name is Libertine Z. Banta & most of my family member calls me either Tin or Tin-tin to shorten Libertine 

Ghost in the Shell character which is also a character in JD Salinger short stories.

Hmmmn.. Mami is my favorite and Haruna is my 2nd favorite hence MamixHaruna... Although if I registered a few months earlier, my username might probably be RinaxTomomi since I love them first before Haru and Mami..  

Orsoheart

i have this username for so long i cant remember when, it used to be ephiasorso derived from ephraim, character in fire emblem : the sacred stone. Orso is bear in italian.

however, i started change it to orsoheart because i like the term lionheart, since i can't just simply said bearheart, i used orsoheart and think "why can't bear have the same glory like lion?" therefore, until today, i am using this username almost in every internet related thing, even my email is the same name. and my guitar is also the same name.  .uhuh.

I've mixed my first name + my surname and got Casvectra somehow  

Mew - it's Meow actually I've just removed the "o" to make it Mew [truth is I like Mew in Pokemon!]

Sch - also it's Schiffer I've just removed the "iffer" a German word for Skipper [coz I also like Skipper on the Penguins of Madagascar] \m/ ^^

#NowYouKnow! ahaha :D

It came from one of my favorite SCANDAL songs: Koi no Kajitsu (pretty obvious XD)

My name + My bands name. Most people knows me only by this name. I'm registered this way in everything, but with the time I think it was a bad idea.

My username comes from a manga that I love: Fruits Basket! Furuba is the shorten version of it!  The "9000" part is from the fact that I was born in the 9th month of the year, and I like to use lots of 0s in my usernames for other websites!! XD

The fx part of my name actually came from the first character I ever made on the very first MMO I ever played, Maplestory. Me and my friend wanted to have matching names so after hours (or maybe days) of debating, we settled on the fx suffix. It's stuck to me in almost all the usernames I've made since then.

From a dish well-loved by the Filipinos otherwise known as chicken noodle soup:
http://en.m.wikipedia.org/wiki/Mami_soup

it can be a portmanteau or Mami-Chan and Offspring guitarist Noodles.

@MamiNoodles

Oh I thought you were Noodles daughter 

@tonymiller It would be an honor if I am Noodles' daughter.

Supposed to be 'Mamitasu' but it was taken (I think) so I had to think of a similar one, thus replacing 'su' with 'chu' :p

my username was invented way back when i was playing ragnarok online long long time ako rougekotoh = my rouge  lol and it is easy to remember

Ryoseki Kun, it instantly pops up in my mind when creating my account here

 .smile.  .smile.  .smile.

it came from Rilakkuma, a japanese bear doll. Kuma means Bear and I add suffix ~kun :D