@Mehnum
I'm not usually the best person to go ask, but I would say (for me at least) no it's not. I mean... it's hard to... well...
This is
really hard for me to explain. It's not usually hard to write a second character. To me it's not really hard to, writing a character of the opposite gender is generally the same as writing any sort of character.
For example my 2nd character in TSU Kaname. I just wrote her with a certain goal in mind. A tomboyish girl, with a slightly outgoing, and loudmouthed attitude that will usually get herself into trouble.
Just try and think of a personality for a character, one that you can easily go with.
Another good example is to plan out what character she would be.
For example with Kaname again. I was thinking of a character that would be considered your "average everyday tomboy", and I began looking for a picture for her. After I found the correct picture:

I kind of went with what I thought is right, and would fit the picture.
"She is kind, caring, outgoing, beautiful, and- Okay she isn't really any of that, but she is outgoing, and... pretty normal for a person with Wind Magic. She also has a tendency to act all tough usually, and has a bit of a "in-your-face" attitude which can get her in trouble some time. Other than that she can be a decent person to hang out with."
Now what I'm trying to say is... well... yes it can be hard, and no it won't be hard. It really depends on the character, the person RPing said character, and well... how well you can remember said character's personality.
Sometimes I even forget a few things like with Andrew (my main character in TSU.) He's supposed to have a Phobia (Scopophobia, the morbid fear of people staring at him. There are several names for this phobia.) Yet sometimes I forget he has such a phobia.
Normally he doesn't like it when people stare directly at him due to his phobia, but he is a relatively normal guy who actually does try to be social. The second you actually stare at him
directly he will completely lose it and will go into a fit of hysteria yelling "Please don't stare at me!" Until the person staring at him stops, he leaves the area, he warms up to a person enough (even then he would still freak out a little if a close friend of his stares at him), or he knocks himself out with a technique he taught himself. Even the thought of people staring at him is unnerving for him. This phobia is something he will try to overcome over the course of TSU.
However sometimes I will downright forget, or don't know how to respond to certain situations and I make Andrew seem quite shy like Trista (TRXD's character.) Yet I have to remember that "Andrew is not shy, he just has a severe phobia of people staring at him."
Also just remember that no matter how you plan certain things to go in an RP, even if you plan things with others. The chances of planned events to go 100% exactly the way you want it is kind of slim as you never know how a certain character might react to certain situations, and you will never know how things might actually turn out. Hence why I try to plan out something in an RP like in TSU. With a standard point A to point B mindset, yet leave the part in between Point A, and Point B mostly blank to allow room for a story to form.
Like say for example in All the World's a Game Season II. I have a small story arc planned in ATWAG II which involves the characters from Elsword, and a few others going back to the world of Elsword in order to stop the Demon General/king Ran (far different from Ran of Touhou.) Yet what happens between the point where the characters of ATWAG II go to the world of Elsword, and when they finally defeat Ran is completely up to what happens between the characters...
GODDAMMIT I ENDED UP RANTING ON AND ON AGAIN!!!
Oh and quick question for you Mehnum...
How long did Progan sleep in TSU? I mean... I don't want him to proceed the time in the RP, because currently in TSU it's supposed to be somewhere between 10:30-11:00 AM.