Kojiro Tokutake wanted to be a doctor since he was a teenager. His grandmother bought him his first stethoscope when he was in medical school. A decade later, he helped her die.

Tokutake, 33, is a gastroenterologist and, in that role, has inserted permanent feeding tubes in elderly patients, many with dementia, two to three times a week.

"It was just a job," said Tokutake, who could complete the procedure in 10 minutes. "My colleagues and I talked about who could do it the fastest when we were still getting trained."