You would think it would be in the shower room

I'm currently staying at a friends place in Tokyo. My friend Chris, Who is also another former AC (AmericanCounselor) from when I was a camp director here. 

Anyway he is gone and I was trying to shower. Unfortunately all I could get was cold water.  I'm looking all over for something to turn on a switch or like a small water heater they have here that instantly heats water and I am finding nothing. 

Unfortunately it's not until after I take my shower I find the thermostat in the hallway that walked by a bunch of times and didn't even look at. 

Upon further reflection I  remembered that many times light switches are outside the bathroom for lights etc. but I didn't think the water heater would also be outside.  Apparently I've been away too much.