I too have used a Japanese name with Katakana characters instead of my western name.

Some websites insist you use a Japanese name and phone number to buy something (theatre tickets, some hotel reservations). Same when you try to buy tickets from a kiosk such as a Loppi machine at Lawsons. A few hotels I have stayed at would not let you book without a Hiragana name, and they always seem a bit surprised when I show up with a very non Japanese appearance.

My surname has a lot of "L's" in it seems virtually impossible for most Japanese to pronounce. Some hotel clerks summon up the courage to ask me how to pronounce it and get relieved when I use a Japanese approximation