The maker of Japan's Umaibo corn puff is raising prices for the first time, in a shock for fans of the "miracle" snack beloved for decades for its crunch and ¥10 ($0.09) price tag.

Tokyo-based Yaokin Corp. is increasing the price of Umaibo by ¥2 apiece to ¥12 from April due to higher costs, according to a person familiar with the matter. It marks the first such increase since the snack — whose name means "delicious stick" — went on sale in 1979.

It is also a sobering reminder that Japan, even after decades of deflation, is not immune to soaring commodity and transport costs. While prices are surging in the West, Japanese companies have so far been reluctant to increase prices across the board, out of fear of losing cost-sensitive customers.