Since the question has been presented to my character plenty of times, I might as well tell the whole story in its unabridged valley girl tone. (Warning- It has reference to Jpop ・ロ・ノ)
So one day I went over to my friend’s house. At the time, she was Aya Matsuura crazy. We spent the day watching and listening to all Aya Matsuura PVs and songs for the most part (I think I can skip over the other torturous Hello Project! stuff that I watched as well). My friend turns to me and says:
Friend: Have you seen the MANSUURA? (The other friend is shaking his head in the background)
Me: Eh? The what?
Friend: You soo have to see this!
Then she starts playing the Goodbye Natsuo PV and points at Aya Matsuura in her best ability to dress up like a guy (with a little goatee and mustache and girly polished nails). For some reason the Ayankeys (Sanrio plush thing) were freakier than her “Mansuura.” We had a good laugh for the rest of the day.
A couple mixed days and months while I was AIM, she would send over screen caps (she just discovered how to make those) of the Mansuura to me mixed in with some funny quotes and captions attached to them. Most of the caps were the ones where the Mansuura was pouting. So among the little AIM group of friends and a Jpop board, the Mansuura became some ongoing joke or pun.
About the same time, I met Armi from the Jpop forums. She kept going on about FFXI and how I should join Q server (I only made one character for another server). So we talked for a bit and I was trying to decide what name to use for the character…
****-This is where literary grammar is destroyed. It is recommended to stop reading after this point if you are sensible to bubbly stuff-:****
Ran: Eh, I have no idea what to name another character.
Armi: Come to Q server! >.< RAWR! Why don’t you use your forum name?
Ran: That is possible. Chances are that it is taken though.

Armi: Hmmm… (Waving Q server campaign posters in the background)
Ran: Well if Ranpha is taken… I will use Ranphamansuura! XD
Armi: hahaha Right on! (She does not believe me). >_< Choose Sandy!
Then I create the character and get to the name box. Ranpha was taken and thus Ranphamansuura was born on Q. The first comment I received as Ranpha: “UR name is LONG.” (You have to love FFXI welcoming committees

)
And that is the incredibly boring story of the name.