I'm going to learn Japanese for free from a tutor.
That's cool. How did you manage that?
I'm just not going to pay the person that is teaching me.
It is wrong to not pay people for the work that they do. That is unethical behavior and it is disrespectful.
But why can't I do it? They are lucky to give me free tutoring.
You're essentially stealing money from the person that you aren't paying, and that is a very serious thing. How would you like it if someone stole money from out of your pockets?