Boo!

I don’t quite understand all this. I mean, I’ve had chats with her during fag breaks and she knows that despite my scary exterior I am a laid-back kind of guy; unless I get angry, of course, but I try not to do that at work too much. No, I am sure I have a reputation for being easy, cracking stupid jokes and not taking myself too seriously.
So why is it I keep freaking out this one colleague so much?

On several occasions I have caused her to jump a mile and have elevated blood pressure. Our television area is flanked by a fridge and once I walked past it, a blind corner, as she came from the other side, causing a “WAH!” with a hand clutched at her chest. Her hand, by the way, before you start insinuating. Then those times I was leaning against the wall waiting for the lift. Another blind corner she turns and another “WOAH!” Me waiting in front of the lift as the doors open on her extracts the Japanese equivalent of a “OHsweetlordjesuschristinamanger!” Or the few occasions we simultaneously tried to open a door but from different sides. That always gets a “OHH!” out of her. And just recently she opened that door as a colleague and I approached it from the side, invisible through the small window. She practically fell over, gabbed the door handle to steady herself and ejected a loud “WAAHHHH!”

In this last situation she was extremely apologetic　despite our demonic laughter. She doesn’t seem like a nervous person, maybe a little shy. And she doesn’t seem to freak out at anybody but me, the company’s only white-skin. Now I am torn between ignoring it, as I should, making jokes about it, to calm her, or exasperating the situation by deliberately scaring the shit out of her, which is probably what I’ll be doing.