This is one of my "month of AUs" that got a burst of inspiration and became it's own story! The AU prompt was "high school best friends" which is something I have a lot of trouble picturing with my OTP, but I tweaked it until I could "see" it, and this is what came out of it!
I hope you enjoy this new experiment of mine! Thanks as always to my "bae-ta" Irritablevowel! (hearts hearts)

It's hard not to be nervous. Usagi pulls the starched pleats of her skirt away from her sweaty legs - it's unseasonably warm for October, the air is thick with the promise of downpour later. Moto Azabu Private High School rises before her like a monolith - so much more intimidating than the comforting halls of Juuban High, where she'd been attending since April.

It had taken nothing short of a miracle to get her into Azabu - barely passing grades, an extraordinary letter of recommendation and her father's check-writing hand. Now she realizes, heart hammering in her chest, this is most undoubtably a monumental mistake. Except for-

"Hi!" a cheerful voice bubbles at her ear, interrupting her thoughts. "You must be Tsukino, our new transfer!" A girl who can only be described as a blonde bombshell is holding out her hand to Usagi, a big grin on her gorgeous face. "I'm Aino Minako. Welcome to Azabu, I'm here to show you around."

Aino - or Minako, as she immediately instructs Usagi to call her - is class leader in Year 1 D class, which is where Usagi is also placed. It's for the kids who don't excel, Usagi knows, although she doesn't say it and neither does Minako. The point is, the blonde says, to be good at one thing, if you can't be at all of them like the A class kids. She's there on an English language scholarship and is captain of the volleyball team.

Usagi thinks of the letter from her art teacher and the sketchbook tucked away in her messenger bag. She wonders if her one thing is good enough, when she can barely add numbers in head, and English might as well be ancient Greek. Minako is chatting away, and Usagi's ears prick at the current topic of conversation.

"-as our student body president," she finished. Minako gestures out the window, where the boys soccer club is finishing up its morning practice in the courtyard below. A fair number of students are watching from the sidelines, all girls.

Although she hasn't seen him in years, Usagi picks out Mamoru right away, tall and slim but broad shouldered. He kicks the ball to a teammate and wipes at his forehead with his arm, swiping at the black hair feathering into his face.

"Chiba Mamoru," Usagi says, feeling her heart in her throat again.

"Yeah," Minako says, "3rd year." She glances at Usagi, amused. "Not you too," she says.

Confused, Usagi opens her mouth but never has a chance to ask Minako to clarify. And soon, as practice comes to an end, she doesn't need to.

"Chiba!" "Chiba, you did so great!" "Do you need a water?" "How about a towel?!" It seems the jumble of female students are out to support their president, rather than the entire team. They surround him as soon as he steps off the field, despite his awkward attempts to politely shrug them off.

"He has a fanclub," Usagi says, needlessly. Of course he does, she thinks, heart sinking to her knees. Far cry from the awkward, crying child she'd given the rose to all those years ago, when she was visiting the hospital for Shingo's birth. The same little boy who was bullied mercilessly from other kids for being an orphan, the one Usagi had sworn to protect (and had, her little 4-year-old chubby self standing up to boys three years her senior, telling them they'd better pick on someone other than her Mamo-chan, or she'd punish them in the name of the moon!). "I should've known."

Minako looked at her curiously. "Do you know him?"

Usagi opens her mouth and closes it again, trying to find words to describe dried tears and skinned knees, clasped hands and giggled inside jokes, the trees in the park becoming castle fortresses (he as the prince, she as the princess and they always beat the evil witch together), an early childhood as close as siblings.

That is, until Usagi's father's magazine makes it big, and the Tsukinos up and move to the rich side of town. The eight-year-old Mamoru promised five-year-old Usagi one day he'd come back and marry her. But he lived in a children's home, and she was too young to write him without her parents help - they were far from interested in helping her.

But she remembers him, all these years later. And when she reads about him being elected student body president in the Azabu newsletter she swipes from her building lobby, she becomes bound and determined to attend Azabu high.

Still, Usagi wonders now, as Mamoru enters the school trailed by - it seems - every girl in existence, does he remember her?

"I used to know him," Usagi tells Minako, finally.

By the time the last bell rings, Usagi feels like her brain could melt out of her ears. Even in class D, the subjects are challenging and, she feels out of her league. But at least it is finally time to clean the classroom and then go to clubs - and she's looking forward to relaxing a bit while sketching in art club.

Then, it's Minako barging into the classroom, tugging Mamoru along by his the sleeve of his uniform. "Hey, class president. Our newest student says she used to know you!" The blonde gives him a sidelong glance and then a wink at Usagi. It's clear Minako thinks she's done Usagi some sort of favor, but the smaller blonde feels rooted to spot under the shocked scrutiny of Mamoru's dark blue eyes.

For a moment there is a charged silence, and Usagi is acutely aware of the the audience they have - the other students' low murmurs and quiet giggles. Who does this new girl think she is? Usagi can almost hear their thoughts. What a silly way to get the student president to notice her...

Because he is, she can't help but notice, extraordinarily handsome. He'd always been a beautiful little boy - the source of some of the bullying, she remembers - his delicate, perfectly aligned features and shocking blue eyes. But now, apparently, it worked to his favor. Puberty definitely did him a solid, as Makoto would say.

"Um," she starts, "it's okay if you don't re-" but he cuts her off with a slow smile, eyes lightening a little.

"Odango Atama," he says, that small smile still hovering around his lips. "It's been a long time."

She nods, biting her lip around a smile. Minako is looking between them with raised eyebrows and a grin, and the other students in the class are exchanging glances and deciding how best to corner Usagi as soon as Mamoru leaves, for all the details of how she got the class president to look at her in that specific, heartpounding way.

'Mamo-chan!' the nickname is almost on her lips, she wants to shout it out and run at him full speed, locking him in a giant hug - her body reverberates with the need to protect him and be close to him. But the teenager standing before her isn't the scrawny eight-year-old who'd been her first -and last - kiss when she was still an elementary school student. And she can't exactly make sense of the intense expression in his eyes.

Mamoru opens his mouth to say something else, but is interrupted.

"Chiba, time for track and field practice," a male classmate calls, walking down the hall with Mamoru's cheering section behind him. One of them runs up, links her arm through Mamoru's and makes sure - Usagi can't help but notice - to press her breasts up against his arm. She has a whistle around her neck, team assistant, Usagi guesses.

"Uh... right. Thanks, Yoko," he says, shaking his head as if to clear it. Looking back at Usagi, he gave another slow, wondering grin. "Welcome to Azabu, Odango Atama. I'll see you around."

She's still frozen to the spot when he and the girl leave, even as her classmates surround her, eagerly exploding in questions and squealing.

Mamoru pushes his hair out of his eyes and leans his head against the shower wall, looking up at the ceiling of the locker room. Usagi. Tsukino Usagi. The name runs around in his head, along with the lame way he left her, standing in the classroom - still diminutive, still adorable, still everything in the world to him.

"'I'll see you around'?," he mutters to himself, into the running water. "What an idiot."

When Aino Minako had accosted him in the hallway he'd been mildly surprised, the girl was one of the blessed few who seemed to leave him alone, but then she cheerfully grabbed his sleeve and pulled him along. "Come with me," she bubbled, and next thing he knew he was being pulled through the door of a first year classroom only to find himself staring, shocked, into bright blue eyes he hadn't seen in years.

His Odango Atama. The little girl who comforted him on the loneliest day in his life, who stood up for him, who played with him when no one else would. There, in front of him, in the flesh.

She still wears her hair the same way, wound up in two knots, the style that earned her his nickname for her - only now the blonde waves fall all the way down her back, instead of ending at her shoulders. And he'd know that little pert nose and flashing eyes anywhere, even if the face they were in was more grown - lips fuller, eyes less rounded.

God, she got beautiful.

Her looks didn't matter at the time, in his shock and joy of seeing her - of wanting to open his arms for a hug, to revert back to his younger self and bury his face in her shoulder like he had so many times before - but now, in the sanctuary of the locker room shower he let his mind replay their reunion like a movie. The endearing way she bit her lip, the sparkle in her gorgeous eyes, the way the Azabu school uniform fell a little on her slim shoulders, clung to her chest and skimmed her belly... the way she'd grown taller but remained shorter than the other girls in the class. And the way he remembered her lips feeling when he kissed her goodbye all those years ago. A fast, dry kiss on chapped lips, secret and hidden in trees by her driveway, before the moving van had taken her away from him for what had felt like forever.

And now she's back. Back and here, in his school, to walk the same hallways and share the same lunchroom.

Breathless, he dunks his head under the water again.

I am pretty sure Azabu is an all-boys school in the manga, but I changed it sorrrrry :) artistic license