Perhaps you should ask Paul or Eva at training tonight!!!!
If you can't wait till then I think that it basically means "thank you". That can be "thank for showing me that technique/for letting me be your uke/for smashing me into the ground/for taking the time to explain that to me".
I think there are other variations though like when we also use it in a sort of greeting context. This I'm not sure of as I don't know Japanese.