There are documents to sort, records to file away, mail to read and bring to Naoto's attention, if it's important. That's something Yousuke can do with minimum instruction, even with the backlog from the hospital stay. More importantly, it's his job.
Naoto, sitting in front of the computer, makes phone call after phone call. Yousuke's pretty sure that should be his job, too.
He doesn't ask.
It's late when Naoto dozes off, in the middle of the same footage Yousuke's watched him replay a hundred times already. Yousuke wakes him—a touch, to the shoulder—and suggests they turn in.