Back in the days when I had a “real job,” I used to get some dirty looks for surfing the web on my breaks. My boss was an a-hole and wanted us to skip those breaks. If your boss walked in and you were laid out in a chair napping that was meant to turn into a bed, I think you would get fired.
If you want to risk it, or if you are the boss looking for some nappy time, this chair from Thanko is perfect. The thing looks like a normal enough office chair in standard mode. Recline the seat back into the horizontal position and flip the legs rest out and you get a bed to sleep in.
You won’t want to lean too much though or you might end up on the floor. The chair sells for 49,800 yen (appx. $599 USD) with tax included and can be ordered right now if you are in Japan. If you live elsewhere, I bet you are out of luck.