Ryouma’s hand stole down to touch the edge of his kneecap, exactly as she had, but his eyes stayed fixed on the doctor. Kakashi wasn’t sure if he was even aware of the gesture. “How’s that?” Ryouma asked.

Niimi-sensei sat back up on her heels and grabbed a model of a kneecap off a nearby cabinet. “Okay, here’s your knee,” she said. She pointed at two grey discs surrounding the joint. “These are your menisci. You’ve studied this in basic anatomy, right?”

Ryouma nodded vaguely. Kakashi’s memory of basic anatomy — taught in the harried moments between battles, missions, and funerals — recalled exhausted medics and an annotated scroll with X’s slashed across the best places to disable an enemy. Knees had been included. He’d learned much more from Rin.

Niimi-sensei visibly recalibrated. “Your menisci act as shock absorbers. Walking puts up to two times your body weight on the joint. Running puts about eight times your body weight on the joint. So when your knee bends, like this,” she demonstrated with the model, “the back part of the menisci take most of the pressure. Without them—” she removed the two discs, and re-bent the knee, making a nasty scraping sound. Ryouma winced. “You get too much pressure on a narrow area, which damages the cartilage that caps your bones. Following me so far?”

Ryouma nodded much more certainly. “That medic who healed it first said I’d messed it up more by walking on it. She didn’t really explain things, though. Just did a chakra-healing — one of those really intense sessions with the seals and everything — and then sent me out. I could run again, afterwards.”

Niimi-sensei sighed. “That’s about standard for the war. Things are better now, but—” She waved a hand dismissively. “Anyway, back to you. When you took a twisting impact and fell on the kneecap, you tore the inner edge of the lateral meniscus. A pretty good tear, I’m guessing. That initial healing fixed the worst of it, but there’s still some instability in there. And probably some scar tissue or adhesions from your body’s own attempt to heal, which is gunking up the joint. The good news is that your knee isn’t locking up on you, which means I can recommend a conservative approach. No open surgery.”

Ryouma drew a deep, relieved breath and let it out. Some of the tension rolled away from his shoulders. “That is good news.”

“Now here’s the stern doctorly warning,” Niimi-sensei said, but her voice stayed warm. “Since you’ve had this for ten years and it’s not improving, we need to do something, otherwise the joint will continue to degenerate and you’re going to end up with arthritis in your thirties. Which’d give you this knee joint.” She leaned back and captured another model. This one had ragged, deflated discs and rough, red edges where the bones touched. She handed it to Ryouma. “If you go down that route, the joint will get more unstable, more painful, and you’ll be at a higher risk for a more drastic tear.”

Ryouma turned the model between long, brown fingers, studying its broken shape. Behind the doctor, Katsuko’s meaningful look could have heated steel.

Very quietly, Ryouma spat, “Damn him.”

Kakashi didn’t think he meant Genma.

Ryouma jerked his chin up, looking at Niimi-sensei with an angry, resigned twist pulling his mouth sideways. “So what you really mean is, it’d end my career anyway, if I live that long. Guess it’s a good thing the lieutenant sent me in.”

“Yep,” Niimi-sensei said, with cheerful sympathy. “Ready to hear your options?”

Ryouma handed the model back. “Lay ‘em out, sensei.”

Kakashi glanced at the ceiling and sent up a brief, silent whisper of gratitude for common sense finally prevailing. Katsuko leaned across the doctor to give Ryouma’s shoulder a quick squeeze.

“One, intensive rehabilitation. In my opinion that’s the next step up from doing nothing, and it’s not my favorite. It’s the least invasive, but it’d be time-consuming and, most likely, a stop-gap. But if you want to get back out in the field immediately, you could consider it. I’d recommend a supportive brace to tide you over, too.”

“I have one already,” Ryouma said. “Helps a little.”