Regardless of their path to get there, over time, roasted sweet potatoes proved very popular in Japan. Stalls were set up at the main guard buildings in post towns along important highways, and their sweetness and aroma – and their affordability – caught on. Signs at stalls sometimes advertised them as "kuri-yori-umai" (better than chestnuts). "In Tokyo, many ate them mixed with okayu (porridge made of rice and barley)," Rath said.