"WAKEY, WAKEY, PARTY MUTANTS!" Michelangelo hollers as he races back and forth, up and down the hall, bouncing between his brothers' bedroom doors like a strung-out pinball. "WE'RE EIGHTEEN TODAY, BROS!"

Inside Leonardo's bedroom, he grumbles under his breath and rolls over, slinging his arm over Destiny. She exhales heavily and cuddles closer to him, nuzzling her nose against his neck and making him smile sleepily.

"Happy mutation day," she whispers.

He brings her closer to him, pressing a lazy kiss to her forehead, and they stay cuddled for a few minutes longer.

Donatello and Raphael emerge from their rooms in varying states of alertness, one still drowsy and in need of coffee, the other awake but annoyed at how they were woken up. Raphael snatches Michelangelo by the back of the shell as he goes racing by, dead-eyed glare on the back of his head, and Michelangelo lets out a sheepish giggle.

"I don't care if you're excited, you wake me like that again and I'll shell-wedgie you so hard that you'll walk funny for a month," he growls. Michelangelo lets out a soft "meep".

"Yikes, Raph," Donatello drones, tying on his mask as he blinks a few times, trying his best to focus through the fog of his mind. "Harsh...on our birthday, too."

"He's been warned," Raphael retorts. "Now, if he does it again, he had it coming."

"Uh, heh...gotcha," Michelangelo says. He clears his throat and wiggles out of Raphael's grip. "Sarina made coffee and I made breakfast, so go get it while it's hot!"

Raphael and Donatello wander off. Michelangelo makes sure Leonardo and Destiny are awake before dashing off to enjoy breakfast.

----------

It's a Tuesday, meaning that Casey, April, Taylor, and Annalise are at school until later. Fortunately, that leaves a lot of time for everyone else to set up. They blow up balloons and hang streamers, bake cake and gather presents hidden away where even ninjas like the turtles can't find them.

Destiny hurries in from the hallway, a small box in her arms, and when she reaches into it, it comes out clutching a strip of white material. She flashes a pointed grin and tosses it to Sarina, who shares the excited grin with a flash of her eyes.

"Masks, I almost forgot," she admits as she ties hers on.

Donatello's mask crumples as he stops hanging up a streamer. "Wait, what masks? When did you get masks?"

"We made them," Destiny says, giving the box a shake and allowing him to see more strips of coloured cloth. "We thought we'd have a theme party and have everyone wear masks, just like you guys." Before the others can speak, she adds in a rambling, excited tone, "See, I've got black, Sarina gets white, Taylor asked for maroon, Annalise has pink, April gets yellow, Casey gets green, and Splinter gets brown."

"Nice," Raphael says, far more focused on positioning a balloon on the platform above the living room.

Leonardo enters from the kitchen and he gasps, his eyes sparkling. He promptly races across the room until he skids to a stop beneath a cluster of Space Heroes balloons, his mannerisms de-aging him ten years in an instant.

"Who got those?!" he exclaims, bouncing back and forth on his feet as he lets out an excited squeal. "Whoever it was, I love you!"

"You're welcome, Leonardo. I love you too," Splinter calls from the kitchen.

Donatello and Michelangelo burst out laughing as Leonardo's cheeks darken.

----------

The final four guests arrive not long after four o'clock. They tie on their masks and gather in the living room, where Splinter cuts generous servings of real, honest-to-goodness cake—thanks, April and Casey—not a worm or a speck of algae in sight. Michelangelo's boombox plays music in the background.

While they stuff cake in their faces, Splinter ushers them to the living room. "I believe we have some gifts for you, boys," he says as he settles into his spot.

"YEAH! GIFTS!" Michelangelo squeals as he bounces into a free space at Annalise's side.

Raphael nudges Taylor, leaning over to whisper, "Seriously, who decided he qualifies as an adult?" Taylor lets out a snort of laughter and shoves him playfully.

"Sensei, if I may, I would like to start," Sarina says, soft and polite as ever as she raises her hand.

"By all means," Splinter says.

Sarina gets to her feet and turns for just long enough to lift Donatello's hands to cover his eyes. "Do not peek," she murmurs.

He smirks and keeps his hands in place when she walks away. She rushes to the lab, shoving the doors open and leaving them like that as she grabs a remote control. She presses a few buttons, there's a soft whirring noise, and a familiar clanking sound resonates in the lair.

Donatello's face goes blank, lips parting. "Is that...?" he mumbles.

"No way!" April gasps as Sarina reappears at the lab doors.

Standing next to the cyborg is a robotic turtle made of green metal, tall and streamlined from its square head down to its legs. It makes a small beeping noise as its antenna twitch and swivel about.

"I give you, Metalhead Mark II," Sarina announces. Metalhead does a deep bow at the waist, one hand folding over its stomach.

Donatello spins around in his seat as his eyes fill with tears. He rushes over and wraps the robot in a hug. "Oh, buddy! I missed you so much!" he cries.

"Uh...that doesn't look like Metalhead Mark I," Michelangelo whispers.

Donatello finally releases Metalhead and turns back to Sarina, dark eyes drowning in awe. "This...he's exactly like I designed him..." he says, almost breathless, a hair away from a mumble. "I never..."

She shrugs and adjusts the remote in her hands. "I...cheated, I will admit. I used your blueprints and the prototypes you built," she says. "I noticed that you could never get yourself to make any real progress, so I finished what you couldn't." She stops talking, shoulders hunching a little beneath his wide-eyed stare. "I...I hope that that's—"

He sweeps her into a long kiss, one deep and passionate enough to make his entire family and Metalhead II turn away. "I love it," he says after he pulls away. "I love it and I love you."

She giggles, brushing at her cheeks as if to wipe away the faint blush. As they head back to the others, Annalise gets to her feet and shakes out her arms, beaming.

"Me next?" she asks. Splinter nods.

Michelangelo starts to vibrate in place, too excited to stay still, and Annalise hurries into the laboratory. After a minute, she rolls something covered in a green tarp out into the open. On top of it is a giant orange bow.

"I can't take complete credit for this. Donnie, Sarina, and everybody else helped a lot," she says as Michelangelo stands up and hurries over. She steps aside, clapping a little as she bounces. "Go on! Open it!"

Michelangelo takes the bow off the top and holds it tenderly. "This bow is so cool! I know just where to put it," he says, toying with the ribbon tails.

"Mikey?" Annalise asks, making him look up. "Your present is under the tarp..."

"I know," he says with a shrug. "But I've gotta appreciate everything."

He sets the bow to the side and grasps the tarp, ripping it off in one fluid motion. Beneath it sits a shiny orange go-kart, complete with a giant "M" on the hood and two comfy seats. One side displays a painted cartoony version of Annalise flashing a thumbs up sign and the other has a cartoony Michelangelo doing the same thing.

"NO WAY! NO WAY NO WAY NO WAY!" Michelangelo squeals.

He tackles Annalise in a hug, then races off to hug everybody else. The exuberant turtle also showers them in happy kisses, which makes all of his brothers squirm away from the affection.

"And it's a two-seater! We can cruise around town together!" Michelangelo exclaims, jumping up and down as he bounces around the exterior of the cart. "I HAVE THE BEST FAMILY EVER!"

He gives Annalise another squishy hug and covers her in more kisses, making her laugh as the tips of her ears turn red. With his present given, Splinter looks between Taylor and Destiny, expectant.

"Well..." Destiny says, giving her wings a flap. "I guess I'll go, but I won't be able to top those gifts."

Leonardo smiles at her. "It's the thought that counts."

Taylor waves her hand at Destiny, urging her to go, and Destiny gets up. She retrieves two cardboard boxes, both with blue bows, and she hands them off to Leonardo with a sheepish look.

"I hope you like them," she says, ears tucking back against her hair.

Leonardo's eyes shine with excitement as he grabs the bigger box of the two and removes the bow. He tears it open and promptly freezes, eyes wide, mouth dangling open. A few seconds pass and Raphael clears his throat.

"What is it, Leo?" he asks.

Leonardo inhales, rears back, and lets out a scream that rattles the lair. "PLATINUM EDITION CAPTAIN RYAN ACTION FIGURE!" he shrieks, thrusting the toy into the air and causing everyone except Master Splinter to cover their ears.

"Nerd excitement is the loudest excitement," Casey mumbles.

Leonardo turns around and brings Destiny into a harried, thankful kiss, cupping her face in his hands. Raphael and Casey make exaggerated gagging noises, and when Leonardo breaks away, Destiny looks dazed.

"I...think you like it," she says, a little breathless.

He nods rapidly and turns to the second box, removing the bow and ripping it open. Another shriek smashes their eardrums to pieces and even Master Splinter buckles to it, hands covering his ears.

"FIRST ISSUE OF SPACE HEROES: THE ORIGINAL COMIC! OH MY GOD!" he fanboys. He looks at the cover again and Destiny can see tears in his eyes. "AND IT'S SIGNED BY CAPTAIN RYAN'S VOICE ACTOR! THIS IS THE BEST DAY OF MY LIFE!"

"It's like he's stuck in caps lock," Taylor says, making Donatello and Sarina laugh.

"Destiny...Destiny..." Leonardo says, turning to her and grasping her hands. "Have I told you how much you mean to me?"

She laughs. "Yes, but...aren't you being a little dramatic?"

"No! I can't even comprehend how you got these," he says, staring down at his treasures as he wipes his eyes. "It's...it's like I'm dreaming. How on earth...?"

She rubs the back of her neck. "Well...Murakami-san actually had a few Space Heroes things and when I mentioned getting you a gift, he offered. He said you'd get more joy out of them than he could."

Leonardo's eyes are starry. "Murakami likes Space Heroes too?" He shakes his head. "Amazing...thank you, Des."

He slides closer to her, slinging an arm around her shoulders, and tucks his gifts at his side as they focus their attention on Taylor and Raphael. Taylor murmurs something like "wait" in Spanish as she stands and goes to retrieve her gift, which is something covered in a thin blanket with a red bow on top.

She sets it in his lap and settles back down, a cheeky grin on her face, and he eyes her for a second. He sucks in a breath and pulls the blanket off, revealing a tiny plastic tank. Inside is a painted turtle, just like Bindo, but her shell is a darker colour and she's a little larger than Bindo.

Raphael stares at her. "A...a turtle?" he breathes. He looks up at Taylor. "For me?"

Taylor adjusts her hair behind her ear. "Bindo needs a partner in crime, sí?"

He nods, seemingly dazed as he lifts the tank up to his eye level. "Hey...little guy, girl...turtle," he whispers. "We're gonna be friends, aren't we?"

The turtle makes a croaking noise and scuttles about the bottom of the tank, making him smile. Taylor pats her thighs, shifting in place as she casts a quick glance to the expectant family members around them.

"What are you going to name her?" she asks.

Raphael thinks for a second. "Uh..."

He racks his brain for any artists that he knows, from Picasso to Monet to Salvador Dali, but none seem right for his new girl. Then, he remembers a painting he saw a while back while browsing the internet, a painting by Raffaello Sanzeo da Urbino.

"Maddalena Doni," he says. Sarina's eyes flash as a coy smile quirks her lips, a knowing look on her face. He lowers the cage and leans over to steal a kiss from Taylor, his gaze fond. "Thank you, Tay." He adds, even softer, "Love you."

"Love you too, mi corazón," she replies.

Casey, April, and Splinter also have gifts for the turtles, like a complete tank set-up for Maddalena, a new toolkit for Donatello, free pizza coupons for Michelangelo, and scented incense sticks for Leonardo. There isn't a need for gifts from everyone. They're happy with that they've got.

Splinter gets to his feet, clearing his throat as he dons a warm smile. "My sons, for eighteen years now, I have trained you, raised you, watched you grow. When I became your father, I wanted to provide you with the best life that I could and now, seeing you as young men, adults...I know that I must have done something right." He opens his arms. "Happy mutation day, my beloved sons."

Michelangelo leaps into Splinter's embrace, the other three following, arms overlapped with one another and eyes squeezed shut. "We love you too, dad," they say, scattered and not-quite-together.

Splinter hugs them closer, eyes brimming with tears of pride.