A.N. The lemon is me, the idea for the beginning and the end is from @chickengirl250.  I might ask her to elaborate on the scenarios, 'cause they're awesome, and then people have clean ones too!  (Like, little oneshots or something, I dunno.  She'd figure that out!)  :)

"It's a trap!"  You yell.

"Ninja!  Jump off, now!"  Wu shouts.  Kai grabs you and jumps off the locomotive, curling his body protectively around you.  The other ninja drop onto the ground around you.  You land with a thud, Kais' body taking most of the impact.  He lets out a muffled groan of pain and releases you.  

"Ow."  He says, trying to stand up.  He wobbles, and you quickly prop him up.  "I think I sprained my ankle."  He winces.

"You certainly did."  Zane confirms, scanning it.  The train blows up in the distance, but he ignores it.  "I would recommend staying off of it for several days."

"I'm fine."  Kai insists, brushing you off.  His leg starts to give out again, and you put your arm out to steady him.

"Thanks, YN."  He says.  "Okay, you win, Zane."  He grumbles at the nindroid.

-Time Skip-

It's a couple of days since the incident, and you finally work up the nerve to check in on Kai.  You have your own agenda, you want to tell him how you feel about him.  You choose a sexy (insert item of clothing here), lace underwear, and daringly don't wear a bra.  Then you go to his room and knock on the door.

"It's open."  Kai calls.  You enter.  Kai's on his bed, he looks up at you, and his jaw drops.

"Whoa, YN.  You look smoking hot!"  Kai says, stunned.  You hear a sizzle, and you're pretty sure that it came from him.

"As hot as you?"  You ask cheekily.

"H-h-a!"  Is all he can say.

"I wanted to check if you're okay."  You say softly, closing the door and going closer to him.

"If I feel half as good as you look..."  He says, staring at you.  "Then again, you always look amazing."  He says, tearing his gaze away from your body, and looking directly into your eyes.

"You mean..."

"I love you, YN.  Ever since we met, I've been trying to figure out how to tell you.  It's sort of why I'm stuck here."  He points at his ankle, laughing.

"I love you too, Kai.  And.. I can think of a way to make you feel even better."  You purr, climbing onto his bed and starting to stroke his chest.

"What are you-"  You kiss him full on the lips, and he wraps his arms around you, deepening it.  You slide your hand down his pants and touch his member.

"Hahgh!"  Kai makes a cute little aroused noise and breaks your kiss.  "Are you sure you want to do this?"  He asks you seriously.

"Mm-hmm."  You reply.  "Anyway, I couldn't disappoint you.  You're so hard already."  You continue, teasing his cock.

"In that case..."  He grins, suddenly flipping your positions so that he's on top.  "I'd better take this off for you."  He says, grabbing your (item of clothing here) and eagerly undressing you.  "YN, you're not wearing a bra!"  He accuses you playfully.

"For you."  You answer, spreading your arms in a gesture that clearly says, 'Do me!'

"That wasn't such a good idea.  'Cause now I've gotta start here."  He says, taking one of your nipples in his mouth and swirling his tongue around it.

"Mmm."  You moan as he does the same to your other nipple, but this time, he nips the bud.  Not hard enough to hurt you, but just enough to send a bolt of pleasure straight to your clit.

He takes off his clothes as well, and gently traces your curves with his finger.  You feel like doing the same once you see his perfect abs, and then you look lower and gasp.  It's stiff, it's hard, and it's big!

"It's okay.  I'll only do it when you're ready."  He reassures you.  You nod, and he looks down and smirks.  "In the meantime, I'll have to take this off for my dirty little pussycat."  He says, grabbing your skimpy underwear and ripping it off, leaving you bare beneath him.  

He starts to play with your clit, his warm hands and tongue working miracles on your wet pussy.  He slowly pushes his fingers into you, in and out, gradually picking up speed, his tongue quickly flicking your clit.  You arch your back, moaning from the intense pleasure he's giving you.  He starts to press his fingers on your point of pure pleasure, and it drives you over the edge.  You cum, and he licks it up.

"You've got a pretty little pussy.  Do you want my cock inside of it?"  He asks.

"Yes, Master."  You breathe.

"Say that again."  He growls, a new lust in his eyes.

"Master, I want you deep in my tight, wet hole.  I want to scream your name while I cum all over your huge cock.  And I want to be filled with your hot seed as you cum inside my pussy.  Please, Master!"  You beg.  "I need you!  Make me yours!"

Kai looks really turned on now.  "If I'm your Master, then you obey.  Open up your legs."

You comply, spreading them as far apart as you can.  He smirks.  "This'll be fun."

He guides his cock into you and impatiently waits for you to adjust to his size.  You can see that he's fighting the urge to just ram it into you, and you know that you calling him Master makes him incredibly aroused.  By now, you're adjusted, so you look up at him pleadingly.  

"Master."

He's watching you with a smile as he slowly begins moving his cock inside you.

"Faster!"  You moan.  He doesn't respond, so you say it louder.  

"Faster!"  He smirks at you and goes even slower.

"Fasteeeer!"  You whine.  Then he suddenly accelerates so much that you scream and dig your nails into his back.  He grunts softly, but he doesn't slow down.  He quickly breaks your barrier as he goes ever deeper into you, and you soon start moaning louder.

"Kai, I think I'm gonna-!"

"Me too, YN.  Just hold it a little longer.."  He starts thrusting even faster and harder, and he's beginning to sweat, his body heating up as he approaches his climax.

"Kai!"  You take his hand and hold it as he tenses up.

"YN, I'm-!"  He squeezes your hand as he releases into you.  At the same moment, you climax and have a shaking orgasm on his thick cock.  "KAI!"

He groans with pleasure and takes a couple more weak thrusts, then removes his cock.  He kisses you all over, and then lies down beside you.  You rest your head on his chest for a while, and he gently strokes your hair.  You turn to him.

"Do you feel better now?"

He smiles at you warmly, with love in his eyes.  "Yeah, thanks.  Do you think you can do this a few times a day?  I'll need it, so I can heal faster."  He smirks.

"For you, anything.  I-"  You hear Jay shouting your name, and you and Kai look at each other.

"Damn!"  You leap up and grab the nearest item of clothing on hand:  One of Kais' hoodies.  You slip it on just as Jay opens the door.

"Kai, have you seen YN-"  Jay stops and stares at you, the hoodie is barely long enough to cover your feminine bits.

"YN, why are you wearing Kais' hood-"  Jays' eyes travel around the room.  The sees the sexy (item of clothing here), your ripped underwear, and Kai trying to cover himself with a blanket, while you blush like crazy.

Jays' eyes go huge with understanding.  "Oh my First Spinjitzu Master, I'm so sorry!"  He shuts his eyes and runs out of the room, nearly running into the doorframe on his way out.

"This is why we shouldn't all live in the same Monastery at our age!"  He yells.

"This is why we should learn to lock doors at our age."  Kai mutters.