A possible concise summary is:
- The video is a prank where the speaker pretends to be a guitar teacher who knows nothing and plays badly.
- He shows his students some simple melodies and chords, but then reveals his true skills and plays some impressive fingerstyle songs.
- He also returns the money to the students and apologizes for the prank.
- He promotes a mobile game, a marathon on improving posture, and his friend's Twitch channel.
- He ends the video with a reference to another prankster.
Here are the key facts from the text:
1. The video is about a prank where a person pretends to be a teacher who knows nothing and can't do anything.
2. The person, Okstar, is actually a YouTuber who makes videos on YouTube.
3. Okstar has been streaming for 27 years and wants to improve his guitar-playing skills.
4. He meets with three different students, Yaroslav, Marina, and another person, to teach them how to play the guitar.
5. Okstar claims to have been teaching guitar for 9 years, but it is later revealed that he has only been teaching for a week.
6. He charges 1000 rubles per hour for his lessons.
7. Okstar plays a prank on his students by pretending to be a bad teacher and then revealing that it was all a joke.
8. He offers to return the money to his students and instead teaches them a simple melody.
9. Okstar promotes a game called Barvikha Mobile and offers a promotional code for 120,000 rubles.
10. He also promotes a marathon on improving posture and offers to return the money to his students if they participate.
11. The video ends with a reference to a theme of matsoni and a promise to make another video.