I'm in a bit of a rush, and I tend to avoid straight Sailor Moon fanfics (never seen the original series), but this one caught my interest.

 Hope this helps. :p

Ken Arromdee wrote:

    It was actually sort of fun, thought Usagi, to look for new Senshi.  There
was no real danger, unless she wanted to count the chance of mistaken
identity, and she could make cool new friends that way--she really didn't
need to put it off at all.

 Not certain about that one -- shouldn't there be spaces when you use a hyphen?

 Unless you're cutting a word off, of course...

    The building that the new Senshi candidate lived in, though, seemed a
little intimidating.  It was a condominium, and if it wasn't that case of
mistaken identity, whoever lived there would have to be rich.  Usagi had never
really known anyone rich before.  She wondered if she should have tried
calling first, but the place was close, and it didn't seem necessary to call
when there was nobody else in the area with the name "Ten'oh".

 Should 'Ten'oh' be quoted in single quotes, since it's not dialogue?

    The person who answered was wearing a boy's school uniform.  'He' was a lot
taller than her, but seemed about the same age.  'He' had blonde hair and Usagi
thought he was positively handsome.  "Hi!" said the person.  "Can I do anything
for you?"

 Putting quotation marks around the 'he' is somewhat of a hinderance, since I've never seen sailor moon, and even _I_ know. :p

 Suggest using just he, with no quotation marks -- at least until the truth is revealed to Usagi, who's PoV this is all from.

    Usagi followed Haruka in, but not entirely believing what 'he' said.
"B-- but you can't be!  You're a...."

    "And you're cute" replied Haruka.

 Hehe...

    Usagi beamed, dropping the sentence she was about to complete.  "Really?
Do you think so?  Anyway I'm here on an important quest...  wait a minute...
my cat's acting funny..."  She picked up Luna, removed an imaginary nail from
her foot, and whispered "Is Haruka really a Sailor Senshi?  You can do the
same sensing thing you did before..."

 ... whispered, "Is ...

    The cat whispered "I think so" as Usagi put her down on the carpet.

 Repetition of whispered? Luna's a cat, so 'hissing' back could work. ;)

    "So", asked Haruka, "would you like to go out with me?"  Haruka added a
little laughter, as if making it into a joke in case 'his' target thought it
was a little too pushy.

    "I, er...  well, I'll think about it" answered Usagi."

 Extra space after the elipse? Not sure.

 ... about it," answered ...

 Extra quotation mark at the end of the sentance.

    "No, it's something different.  This may seem like a strange question,
but Haruka, what do you know about the Sailor Senshi?"  She'd have to be
careful in asking, though.  Luna didn't have Haruka's magical pen.  It wasn't
as easy as handing over the pen and asking Haruka to shout 'Crossdresser Power,
Make Up!'.  Usagi would have to hint about it, find out what Haruka knew and if
she had gotten her powers yet....

 Ugly, but there should be a comma before Haruka's name, shouldn't there?

 I think you can treat the 'Crossdesser Power Make Up!' complete without adding a period to the end. Ie., ... Make Up!' Usagi...

 Also, you slip from 'he' to she here? Intentional? Seems a bit sudden.

    "Oh" replied Haruka.  "I've heard of them but I don't know a lot about
them."

 Commage.

    "Well, we're..."  Luna tugged at Usagi's skirt; she hastily withdrew the
sentence.  "*I'm* looking for Sailor Uranus and I know she's from around here.
Do you know anything about her?"

 I'm not certain about that -- isn't the sentence with the semi-colon technically using Luna as the subject of the latter half?

    "A fan of yours?  What do you do?"

 Haruka: Why, I... SING!

 Senshi: The Musical.

 Hm... Better not.

    The expression of surprise on Usagi's face looked, to Haruka, to be
genuine.  "You're really not?" she answered.  "I'm a race car driver.  You can
look around if you want to, I have some awards from my last few races on the
shelf over there, and they did a short article on me in a magazine recently."

 PoV shift from Usagi to Haruka here?

    "So what's this all about?" wondered Haruka.  "You couldn't have come over
here just to ask me about girls in short skirts.  Could you?"

 Usagi: Do _you_ see a 'lime' or 'lemon' tag on this fic?

 Haruka: Geez. You're becoming as jaded as the Ranma cast...

 Aside, though, that's a funny line. :p

    "Well, yeah.  It's been really nice meeting you.  I probably should
go...."  Usagi wondered if Jehovah's Witnesses felt this way.

    "Okay, see you around.  And one last thing?"

    "Sure...  ask whatever you want...  I barged in here on you, after all."

    "About that date...  I know you have my phone number.  Why don't I get
yours?  Just in case I might want to talk to you some time again, you know.
Or you could call me first."

    "I didn't say 'yes' to the date", replied Usagi, "but I guess it couldn't
hurt."  She fumbled in her pocket for a gum wrapper and, as she was about to
write it down on that, Haruka passed her a real piece of paper.

 Heh. She takes being called 'Dumpling Head' pretty well.

    The meeting of the five girls that day happened to be a park, which had
been Ami's suggestion.  It really was a nice place, thought Usagi; it was all
very pretty, and the smell of the plants and flowers and the sound of the
animals made it feel much more alive than a city street.

 Sounds of the animals? In a japanese park? Birds... squirels... what else?

    "That sounds like it would be much uglier" said Makoto.  Usagi really
didn't think it would be that bad...  Haruka lived in a big building complex
and that place looked great.  It even had plants around the outside.  She'd
love to live in a big building like that.  Tear down the park, and build a
*big* castle made all of crystal on the spot....

 Hehe...

    Minako, whispering to Usagi discreetly, wondered.  "I thought Rei was
supposed to be this big spiritual person.  She should be worried about what
happens to the birds and animals when the park is gone.  Not about going out
with a guy to the park.  That's for us!"

 Hah!

    "She's like just about everyone else", replied Usagi.  "She likes guys
too.  You know, I was curious about Mamoru myself!  He's pretty handsome, and
he might always end up being Tuxedo Mask.  But on the other hand he's pretty
suspicious.  I don't know if it's good for Rei to go out with him either way."

 They already have suspicions that he's Tux-boy?

    "Do you think she could really get him to go out with her?"

    "I don't think so.  She doesn't even know where he lives.  She'd have to
bump into him on the street or something."  Saying that, Usagi began to imagine
that Rei might deliberately do just that.  It would be pretty funny.  But it
couldn't work; could it?

 The semi-colon seems out of place there... perhaps an elipse or a dash?

    Usagi thought.  Briefly, and then she let her character lie motionless to
look at the new potential catch.  Fortunately, Minako, the blonde on the
other side of the game, had done the same.  The teen smiled at Minako, who
nearly glowed, her obvious happiness announcing to the world her pride at
attracting the attention of such a handsome guy.

 Is the description of Minako a bit redundant? We already know that Usagi's playing against her from earlier.

    "But you're a racer.  Isn't playing racing games like going to school all
day and then reading in order to have fun?"  (To her credit, Ami barely
blushed.)

 I don't know that the parentheses are neccessary, here. Seems a tad jarring, really.

    "Haruka.  I met Haruka during my search for the you know whats."

 you know whats -- 'you know whats' (?)

    "Oh, yeah, I meant a pole!  Did you know that I always wanted to meet you,
Mamoru?  I'm Hino Rei."  She bowed.

 First name already? That's very forward of Rei...

    "Sure" said Mamoru.  Rei thanked whatever kami was watching over her that
day.

 "Sure," said ...

 Actually, you're using an unfamiliar convention to me...

 I suppose it would be:   "Sure",

 Which looks odd, but...

    Meanwhile, at the door, Usagi was astonished.  Rei had done everything
wrong.  But somehow Mamoru had thought it was cute, or amusing, or that she
meant well...  Usagi would have to follow them to see what was really
going on.  Such a handsome guy was too dangerous for Rei.  That was it, she
needed to watch them to protect her.

 Hum. This area feels a little forced.

    Usagi stepped inside the arcade and positioned herself right next to the
person she was looking for.  "Haruka!" she exclaimed.  "You wanted a date with
me..."  (At that, Minako nearly fainted.)  "Well, since I wanted to go and
watch Rei, and you wanted to go with me somewhere, it would be a perfect
match.  So let's go!"  She reached for Haruka's hand.  (Minako nearly fainted
again.)

 The parentheses still feel uncessesary here.

    "I don't know, Usagi.  We've barely met.  I hope you won't...  I really do
like you."

 Fast, isn't it?

    "If you want to make it more normal", said Usagi, "we could have some tea?"
Haruka was rich, after all.  Haruka could afford it.  And...  "And I'd like
some chocolate cake myself."

 Heh...

    "Really?  You looked older than that to me.  Hey, I hear something."
Meanwhile, the waitress brought each person's order over, Haruka only having
ordered tea.

 'each person' sounds kind of dry.

    "It's Rei and Mamoru.  We got to telling each other our ages before they
did...  I can't believe he's 20.  I guess he likes younger girls!  And that
means I..."   Usagi looked at Haruka, sitting right across from her.  Haruka
looked so earnest, like someone who really did want to be with Usagi.  It
would disappoint Haruka pretty badly to say "I still have a chance with
someone else."  Not to mention that it would make Usagi look like a fool,
and a little of that goes a long way.

 say "I -- say, "I

    "It's not that hard.  I don't have entrance exams--Mugen Gakuen has a
high school too, so everyone can just move up into it.  And while I do
win some money from races, it's more of a hobby than a job.  I wouldn't
call that a career."

 high school -- highschool

    "There's just something about being a prince that's not right for me.
Besides... what if you were someone's enemy in the past.  You shouldn't be
forced to feel that you hate them just because of that.  Or what if you were
engaged to two different people in two diffferent lifetimes, or if in a past
life you were engaged to your brother...."

in the past. -- in the past?

    "Hi Usagi!" said Rei, standing in the exact spot Usagi had referred to.
Usagi's startled jump took her far enough into the air that Haruka had to
catch her when she fell down.  "Are you here on a date?" asked Rei.  "Your
boyfriend's nothing compared to Mamoru.  You're not watching us, I hope?"

 That's pretty snide of Rei.

    "Come on", said Haruka.  She grabbed Usagi's hand and ran away, dragging
her along.  "We don't want to miss the showing, do we?"

 Heh... of course, Rei should also wonder what Usagi was doing in the bushes with her 'boyfriend'...

    "Dumpling...  Usagi" asked Haruka.  "Is something wrong?  I was going to
take you to see the Ranma 1/2 movie.  It's for everyone...  either girls or
guys.  Or maybe we could see something live-action instead."

 Hah!

    "Haruka, I may be stupid, but I'm not dumb."  Wait, thought Usagi, that
didn't come out right.  "Look at you.  You're all suave and mature and you
even look older...  I wouldn't be surprised if you did go all the way."

 Someone's channeling Minako. :p

    "Don't think so little of yourself, Usagi.  From what I know of you I
think you have the potential to be a very mature girl.  And I don't mean that
as a pickup line.  Why don't we go see the movie anyway?  I'm sure you'll
enjoy it and hey, if you want to be like me, we can see the same movie."

 Why not, "Even if we can't be more, we can still be friends?" Cliche, perhaps, but reasonable, here.

    Suddenly a woman around Mamoru's age crashed into Haruka from behind.  A
paper bag she was carrying ripped, spilling vegetables and tofu blocks all
over the sidewalk.  "Excuse *me*?" said Haruka.

 Why is 'me' emphasized? Seems awkward.

    "Oh, I'm so sorry" replied the woman, pushing her long greenish-black hair
back with a hand.  "I really should watch where I'm going.  Are both of you
okay?"

 sorry" -- missing punctuation, not sure how you want to handle it, since you seem to keep the commas outside of the quotation.

    Usagi pulled Haruka aside with the strength of an excited 14 year old,
which easily beats that of a calm 15 year old (even a mature one).  Quickly
whispering, she demanded "Haruka, let me slap you."

    "What?"

 Hmm...

    "Fine.  But please tell me about the other stuff later, okay?"  She winked
at Usagi.  "Don't hurt me too much."

 Usagi? Hurt Haruka?

    Haruka rubbed her face.  Usagi ran away.  Now, she wondered, just how was
she going to explain this to everyone else?

 And what would it accomplish?

    "The Silver Crystal will help me and I need to get her these papers!"
Small Lady waved around several rolled-up sheets, that seemed to have
Serenity's mark on them.  Her little hands were clenched tightly around them
as if they were the most important thing in the world.  What was going on?
Pluto had foreseen the exact moment when Small Lady was to appear.  She didn't
have any papers.

 'seemed' to have? That sentence scans awkwardly.

    There was a signature and one last sentence before the information--
information that Pluto dared not let Usagi get.  But she didn't understand it.
She mulled over that last phrase as she tore the papers up: "And to you and
the Senshi of the 20th Century: Be excellent to each other."

 information --   this seems set up to segue into something, but nothing's there.

 Bad, bad, bad joke. :p

 Now. A few more weeks of C&Cing everything I see... and I'll catch up with Mr. Sommer!