Princess Tsunade was having a bad day. She was the 5th Hokage, she shouldn't have had to be a substitute for a stupid Academy class. But here she was, in front of a bunch of stupid kids.
"Alright class." said Tsunade as she began drinking some sake. "I'm supposed to teach you about some random history stuff. I'll teach you about the...Sockdemons? Oh, wait, that says Sannin."
"The Sannin were the three great shinobi of the the leaf, personally trained by the 3rd Hokage."
A random kid threw a paper airplane, at Tsunade, who dodged without looking. Then, she turned around and shattered Iruka's desk with one punch.
"Look, kids. We both don't want to be here, but as long as I am the teacher, you midgets will shut the fuck up, and STOP THROWING FUCKING PAPER AIRPLANES AT ME!"
Tsunade continued her lecture on the Sannin. "Jiraiya was a perverted criminal, and still is a perverted criminal. Orochimaru was a gay pedophile, and still is a gay pedophile."
Some kid snidely whispered to a friend. "Tsunade was a drunk maniac, and still is a drunk maniac."
A shadow fell over him, and he got thrown into Mt. Hokage for insulting her. After that, everything was quiet.
The next day, Iruka began crying when he saw his broken desk, and all the empty bottles of sake that Tsunade had drunk from his desk.