PLUS Stationery's Air-in eraser slowly reveals Mount Fuji with each mistake you make. They were originally a limited release in the summer of 2019, but due to high demand, they brought them back as a permanent collection, yay!
The casings have traditional Japanese designs and motifs. They make a wonderful little gift.
Two colours available:
Classic cool blue
Limited edition sakura pink
Needless to say, the whole range of Air-in erasers are great quality. Expect no less from these ones.
Check out nippon.com's excellent article for instructions on how to create the perfect Mount Fuji shape with your eraser.