Picture from Calbee.
Mini Stop convenience stores is offering this abomination before the potato gods for a limited time. The concept is potato-chip-like shells with mashed potato filling inside. This type of carb-on-carb action reminds me of when I was a kid and used to make "mashed potato sandwiches". However, this version seems quite a bit more incestuous than the wedding of bread and mashed potato.
A cup of this treat can be yours for about $2 (198 yen). The fact that the inner potato is yellow orange (and as far as I can tell, it's not sweet potato) is a bit scary, but otherwise, this may offer some kinky textural qualities.