News about the nightly races apparently did not spread fast or far, and Splinter was scarcely a block from the park before it was clear no one recognized him as a breakout street-racing star. They spared him hardly a second glance, and so he paid them no mind either.
Thus it was that Splinter did not notice the motorcyclist pulled up next to him at a red light. He revved the engine simply because it was enjoyable to do so, and did not realize that it had sounded like a challenge until someone spoke.
"I don't race. I just ride."
It took him a moment to figure out where the voice was coming from. The motorcyclist, barely even visible below the Shellraiser's high window, was wearing a helmet that hid their whole face, and had looked neither left nor right while making this pronouncement.
"You do not want to race me anyway," Splinter said. "I am undefeated."
The silver helmet, with its dark visor, tilted up. "Is that so?"
"It is," Splinter said. He draped an arm casually through the open window. This was a very long red light.
"How long have you been racing?" the motorcyclist asked. The voice was muffled, but Splinter was beginning to suspect it was a woman. The figure, outlined in black riding gear, did not seem quite right for a man.
"... Three hours," Splinter admitted.
The rider snorted in a distinctly unfeminine way. "Well, points for honesty."
The light changed, and Splinter began to ease forward. "Hey, wait," said the rider, ignoring the chorus of honks that immediately started up behind them. She held up her smartphone; its glowing screen seemed to be awaiting some sort of input. "I just got into town. I was supposed to be looking up a hotel, but you distracted me. Can you point me to someplace not too expensive?"
Splinter had a sudden flashback to the perversely joyful moment in which he had realized that he was doomed to spend the rest of his life hiding in the sewers, but at least he no longer had to pay New York rent. "There is no place not too expensive," he said. The light turned back to red. Someone in the line of traffic screamed expletives. The rider did not react.
"Well, damn," she said, reaching back to put a hand on the bundle packed neatly behind her seat, confirming it was still there. "Guess it's a park bench. Got a favorite park?"
"I can offer you accommodation," Splinter said. He wasn't sure why.
The rider looked at him appraisingly - or at least seemed to. "Yeah, why not?" she said, as the light changed to green again. "Lead the way."
Splinter did - though he seriously considered dropping an oil slick and speeding away from the mysterious motorcyclist. What had he just done? What kind of person would agree to such an offer? Certainly not a person he should be welcoming into his home. But it wasn't like he could allow her to spend the night on a park bench…
The next thing he knew, the rider was following him down the hidden ramp, and then she was parking next to him in Donatello's lab. With practiced moves, while Splinter watched from the safety of the Shellraiser's cabin, she dropped the kickstand and leaned the bike to rest. More than that, she checked the carefully-secured bundles, examined the tires and fenders for damage after what had apparently been a long journey, and tucked the motorcycle's key into a pocket of her close-fitting riding gear.
Definitely a woman.
Only then did she lift off her helmet, letting long black hair swing free.
"Yuki," she said, tucking the helmet against her hip. "And you're James Bond, I presume." She took a moment to look appreciatively at the Shellraiser, the ramp she had just come down, and the fantastical underground laboratory.
Splinter stepped out of the vehicle.
"Or not," said Yuki.
Splinter bowed slightly, noting Yuki's Asian features and the way she only watched him curiously, without backing away. "I am Yoshi," he said. "Welcome to my home. I hope you find it comfortable for the night."
"What is this place?" Yuki asked. Already over any shock she had experienced from seeing Splinter in the light, she set her helmet on the motorcycle seat and wandered to Donatello's desk, picking up a beaker full of something so viscous it was nearly solid.
"My son does science projects," Splinter said.
"I'll say." Yuki put the beaker down, ran her eyes over a page of scribbled notes, then moved towards the door. "Are you going to offer me something to eat, Yoshi? It's been a long day."
Over the next several hours, Splinter learned that Yuki spoke Japanese, had a dragon tattoo curled along her spine, and was in a relationship with someone in California.
"It's complicated," she said, by way of explaining - at least partially - why she'd thought nothing of not only following Splinter home, but accepting his invitation to roll out her sleeping bag in his bedroom. "We're still figuring things out."
"And where is he now?" Splinter asked.
"At home," Yuki said. "He doesn't go out much."
"Nor do I," said Splinter.
"Huh," said Yuki. "Guess that's my type."
Splinter was silent. Yuki had explained why it was not a problem for her to spend the night with a man, but he did not know how to ask why she was unperturbed by spending the night with a giant rat.
She was perceptive, and subtle, and what she said next may or may not have been an answer to what Splinter was thinking. "I don't know when I'll be in New York again," Yuki said. "I promised myself I would have a crazy adventure while I was here."
They lay down together, and Splinter was not sure he minded being called a crazy adventure.
*I'd love to claim Yuki as an original character, but she is not. She appears in the mystery novel sequels to the TV show Monk, where she develops an unlikely but beautiful relationship with the title character's brother. The actor who played Monk himself went on to voice Splinter in 2k14/2k16. So it all makes sense.