Re: Problems in a dojo
The Cho should step in and say, regardless of who is at fault, cut the crap, shake hands and be done with this nonsense. But since he is unwilling, you should leave. Make sure you tell your teacher why you are leaving. Include the fact that this senior feels that the only way to resolve the issue(s) would be if the two of you duke it out.
One lesson from this, would be see how you interact and influence others. You do play a part in this, regardless of the size of the role or your intent. I think this is the most interesting aspect of Aikido, the interaction between practitioners. If you bully your uke chances are they will try to do the same to you. Through practice a lot about yourself is revealed. For me anyway, its been an eye opener.