Plot
Kimani is working on a side project for the guys and gets so caught up in their work that they end up listening to music on their headphones which results in Kimani singing and dancing a bit while they continue their project, unknowing to them that a certain soft shell walks in and hears the music.

It was a decent day in the lair as the gentle 'whirr' of tools was heard and Kimani was in the tank garage, they were working on a new vehicle for the guys as it was a side project they had been working on for quite a few weeks now.

Kimani moved the welding goggles away from their face and smiled a little as they set down the torch once they shut it off, going to the workbench as they grabbed their energy drink which had zero sugar.

Much like Donnie, Kimani would have an energy drink or two but they preferred zero sugar energy drinks. Kimani took a sip and set the can aside before looking back down at the blueprints for the vehicle they were making, it was a patrol vehicle they decided to call the Stealth Bike.

"Okay, just a few more parts to finish up and then the shell cover feature and it's good to go. Better text Mikey to get some food for later." Kimani mumbled, they grabbed their phone and sent a quick message to Mikey to order up some pizzas as Kimani set their phone down on the workbench once they sent the text.

Kimani stretched and then grabbed their headphones that Donnie made for them, not only did they have noise cancelation function to them but they played music too that Kimani had saved in a SD card. Kimani slipped the headphones on and tapped up the volume as they then took hold of a wrench, twirling it in their hand with ease as they then tightened up some bolts.

Kimani heard their favorite song come up on the headphones and they smiled before they gave a soft hum to the song, tapping their foot to the beat while they worked. Kimani lightly sang along with the song as a small smile graced their lips while they worked and sang.

Meanwhile, Donnie was leaving his lab to grab a drink and the soft shell gave a tired yawn but shook off the sleepiness as he made his way to the kitchen. Lost in his own thoughts at the time but his train of thought trailed elsewhere when he started to hear a voice singing.

"I look for his arrows every day
I guess he got lost or flew away
Waiting around is a waste
Been counting the days since November
Is loving as good as they say?"

Donnie arched a painted brow in puzzled confusion but followed it to find the source, he saw it lead to the tank garage and approached quietly as not to scare whoever could be in the room. He peeked into the tank garage and saw Kimani working on their new vehicle but took notice at seeing that Kimani was dancing a bit to themselves while they sang to the music on their headphones, their singing voice rather pleasant to hear and even realize what song they were singing since he faintly remembered hearing it from Mikey's room before.

(A/N: My small headcanon was that Mikey and Donnie like listening to J-pop/K-pop music)

Donnie listened to Kimani's singing for a bit longer and he felt a small smile grace his face as he tapped his foot a little, he then got an idea and decided to try and surprise Kimani as he made his footsteps light and soft as not to be detected by Kimani.

He made his way to the shapeshifter snake Yōkai and Kimani kept working, singing and dancing a bit to themselves as Kimani had their eyes closed for a moment since they got lost in their music.

"Now I'm so lonely
Oh, I wish I'd find a lover that could hold me
Now I'm crying in my room
So skeptical of love
But still, I want it more, more, more.."

Kimani kept singing to themselves and smiled before they eventually heard something even with the headphones on so they stopped singing for a second, hearing singing that wasn't their own and they opened their eyes a moment as they recognized the voice of who sang along with them.

"Hopeless girl is seeking
Someone who will share this feeling
I'm a fool
A fool for love, a fool for love..~"

Kimani turned around and saw Donnie as a dark blush spreaded across their face out of embarrassment since they were caught singing and dancing, Donnie chuckled softly and he looked at Kimani who took their headphones off. "H.. how long were you standing there?" Kimani asked.

"Long enough to see you dance and the fact you've been singing like a literal angel. Where did you even learn to sing like that?" Donnie asked, he was honest when he wanted to be but he could even be brutally honest so he didn't want to go too overboard with it as he hadn't given many compliments before but he hoped that it was enough.

"No where, I just sing a bit in the shower.." Kimani admitted, they felt their face burning up from their blush and looked away before they turned back to looking over their project as Donnie took a peek as well, whistling a bit in amazement at how far Kimani had gotten on making their new vehicle.

"Need a hand?" Donnie asked, he was more than willing to help out plus he figured that the job would get done quicker with am extra set of hands.

"That would be greatly appreciated, thanks Dee." Kimani said, they smiled a little and then moved aside as Donnie grabbed some tools and he walked over to Kimani as the two of them got to work on the new vehicle together and occasionally singing to the music Kimani had or dance together even if it was for a short moment.