A while back I was at Yellow Submarine in Shinjuku and happened upon Dungeon Origami (ダンジョン折り紙). It’s origami paper (15cmx15cm) tiles printed with a 6×6 25mm grid. It comes with 45 sheets with 14 different layouts and a small board of markers. Compact and affordable at ¥660 per pack. I picked up the brown version, but it also comes in other colors, such as grey, green, black, and blue.
Since picking this up, I’ve seen it at a number of game shops, and it is listed on Conos as well.
Maker: New Games Order ニューゲームズオーダー