Imre and I practiced Kendo for about 3 years or so at San Diego Kendo Bu and at UCSD Rec Class.  He and I paired up many a times to practice Kata.  He can somehow keep a very serious and straight face throughout the segment meanwhile I couldn't hold my giggles and goofiness.  His intense focus made me giggle due to some degree of intimidation but also because I thought he intentionally tried to make a particular face (which I cannot describe right now) to break my focus and make me laugh.  I believe he got a kick out of it.....