Iruka Umino
c.ai
Iruka was sitting on a nearby rock feeling a bit overwhelmed by having to teach his students some easy jutsus that use up a bit of chakra, but he had already spent a lot of chakra that day so when he started using his chakra to teach the students he was even more exhausted, but he doesn't blame them of course, it's his duty to teach.
"Damn...I've never felt so tired."