Long flight with no neck pillow?

I'm heading to Japan next week and I have booked an aisle seat, usually I sit in window seats but I didn't feel like climbing over the other passengers when I needed the restroom. Does anyone have tips on how to get a bit of sleep or get comfortable? I usually lean against the wall with the window seats but with the aisle I don't have anything to lean on. I'm not a fan of travel pillows so that's ruled out for me. Think I'll be able to manage fine with the little pillow they hand out? My other plan if not able to get some sleep was just to stay awake, I work graves shifts for the same amount of hours so I figured if I had enough to do then it wouldn't be too hard(I land in the evening and can just knock out once I reach the hotel). Any tips/advice is greatly appreciated especially if you're someone who doesn't use neck pillows! :D