How to tame wild boys

Since August, I've been teaching four soccer boys in my condo.
All of them are six graders. One of the mothers is my friend and she said...
"They are too wild to be seated for a class and always very noisy... We, mothers, want them to prepare for English learning starting from junior high school. But we're sure they would drop out if we have them enter an English school or something because of their BAD behaviors. ...So, I would like you to teach them. Will you do that for us?"

When I had the first class with them, they were very cute kids & not noisy at all.
I said the mothers, "Hey, relax! They have no problems!!"
But you know, mothers always know their kids more than anyone...
As they get to know me, they have been getting to become "usual themselves" in front of me.
They really can't stay being seated!!
They are running, chasing another boy, slapping the other by a slipper, pushing someone away...
Whenever I say, "don't!!" Boys say, " どんと押せって言った？”(Did you just say, "bump him hard?") and keep doing that...

I teach them every Friday, so, sometimes I have a wedding emcee job the next day.
I'm really afraid if I lose my voice the next day because I can't stop screaming, "Stop!" or "Don't!!" or "Come here!!!!" or something, like I did in a four-year-old class at school.
Sometimes I'm really upset their rough behaviars!!

Now, their class is the hardest class ever.
I know how to use their energy for having them compete by English games. So, I let them do basketball, soccer, bowling, using some kids props. However, since they're already "low-teenagers," they get tired soon for a game and try a new one.
Therefore, I need to take at least two hours to prepare their class.
It takes time, is tiring, and I use my precious time on my day-off, I mean Friday...but I know it's worth to keep having the class for them, and for me.

For me: I can learn a lot by using another textbook other than my school's. Right now, I don't teach boys in the five & six grade, so getting to know them would make me an experienced teacher for the generation.

For them: They get to take in English, gradually. For example, even when they curse each other, they ask me beforehand, "How do you say 豚 in English?" Then, they scream "Hey, pig!" each other...
Oh, most importantly, they never skip my class and never late. Also, they never neglect homework! They are good students, aren't they?

Yesterday, the wildest boy saw the second wildest boy running, and said.
"Hey, you! You're such a kid! Why don't you go back to first grade and start over with the kids!!"

...Was he reading my mind!?
Teaching kids is great cause I can see the phase of their growing on site!!