Returning to Obito with the Sharingan and a Katsuyu, Hatake Sakumo found the young man looking completely absent-minded, radiating an air of dejection.
"Obito, what's wrong?"
Hatake Sakumo looked at him strangely. "The Sharingan has been brought back, and Katsuyu will help transplant it. You..."
Hatake Sakumo said all that, only to realize that Obito did not so much as move his eyes.
Helpless, Hatake Sakumo could only force the issue. Turning to the thumb-sized Katsuyu resting on his shoulder, he said, "Katsuyu, I'll have to trouble you."
"No problem."
Katsuyu replied gently.
Then, Hatake Sakumo placed Katsuyu on Obito's face.
Katsuyu was highly skilled. She immediately numbed the nerves in Obito's right eye, deftly removed his eye, and Hatake Sakumo seamlessly took out the Sharingan and placed it into Obito's eye socket.
Katsuyu promptly used Medical Ninjutsu, beginning to connect the nerves between the eye and the socket.
After some time, the numbness gradually faded, and Katsuyu successfully completed the entire transplant!
"Gasp!!"
Obito suddenly sucked in a breath, awakened by the stabbing pain in his eye. Only then did he see Hatake Sakumo. His expression froze. "Uncle Sakumo?"
"What exactly were you thinking about just now?" Hatake Sakumo shook his head, looking as though he could not bear Obito's lack of drive. Then he said, "The Sharingan has already been transplanted. Try it out."
As he spoke, he reached out and took Katsuyu off Obito's face.
"What is this...?"
Obito rubbed his eyes, looking somewhat disgusted. "It's all slimy. Is it a snail?"
"No, I'm Katsuyu." Katsuyu answered gently, not offended in the slightest.
"Katsuyu?" Obito rubbed his eyes as he tried to recall. "I feel like I've heard that name somewhere before."
"She is the Fifth Hokage's Summoning Beast and specializes in Medical Ninjutsu," Hatake Sakumo said.