Ah, 'tis so good to be in the company of people concerned with courtesy. In case any one else has noticed too, we're in a society(American) that is tragically short on politeness and courtesy.
I've paid alot of attention to this subject because courtesy is part of the backbone of healthy relationships. So here goes my spiel:
Oneigaishima(su) is the future tense of the word thank you. It means thanks in advance(a.k.a."please") for what we're about to do together.
Japanese Hierarchy can be brushed aside at this point. Agreements to train are mutual relationships(you are the universe and so is your partner) and the voicing of a request is only appropriately responded to with the exact same courtesy, 'onegaishimasu'. The subtlety with which this request (eye gestures, a grunt, a nod) is made is as subtle as all language and takes an effort to gain nuance The words are signals that you will be treated with deserved respect for your offering. This applies in all training.
It is very important to understand the words that you are using so that you may use them appropriately. Onegaishimasu is not interchangable with Domo Arigato gozaimashita strictly based on word tense. Gozaima(shita) is past tense and refers to what has already happened.Onegaishima(su) is future tense.
As for the amount of use of courtesy to use (i.e. Rei etc.), "when in doubt, bow":
. If you have a teacher who demands special treatment or exclusive courtesies you may regard these as 'red flags of the ego'
. Pay close attention!!!
If we are to locate our real selves through training then we need to offer as much courtesy to ourslves as to others. Most of us need a little help in the self esteem department and being treated with basic courtesy is a most beautiful way to achieve good spirit. Some other great Aikidoka once said, " Love your neighbor as yourself." I just can't seem to remember who said it.