Getting caught by your teacher for any act of mischief is not a good thing.
A teacher from a school in Fukuoka City, Japan, was merely doing his job and had warned one student to put away his mobile device as class was in session.
Ironically, he was punished instead after that student didn't take the scolding too well.
Instead of just putting his tablet away, he decided to confront his 23-year-old teacher.
In a video that has since gone viral, the 16-year-old student could be seen getting close to the teacher and launched his assault by kicking his calves first.
He proceeded to violently kick the teacher two more times and followed through with a strong punch to his back.
The student had even grabbed his teacher's collar but stopped when he was finally yelled at by the teacher.
The incident took place before a classroom full of students - one of whom had filmed the incriminating video and posted it in a group chat on mobile messaging app LINE, reported Huffington Post Japan.
While it happened, the other students in class could be heard laughing.
The 43-second video clip was later posted on Twitter by another student and it soon spread like wildfire on social media.
At press time, it has garnered over one million views on YouTube after Otaku News published it.
According to TokyoReporter.com, school officials have announced plans to lecture the student body as they took issue with those who had erupted in laughter during the assault.
Meanwhile, the attacker was arrested by Fukuoka Prefectural Police on the night of Sept 29, said Huffington Post Japan.
He admitted to charges placed upon him and was quoted by the police that there was "no mistake" he committed the assault, said TokyoReporter.com.
The report added that the teacher was left with minor injuries, including bruises.
Under Japan law, teachers are not allowed to physically hurt students under any circumstances.
According to The Japan Times, the education ministry publishes research papers for every new school term to guide teachers on how to discipline students and also lists the do's and don'ts - including how long a teacher can make a student stand before it becomes illegal.