Founded in 1904, Mycoal Co., Ltd. has been selling disposable hand warmers since 1978 and was the first to sell stickable warm packs in 1988. Mycoal is the most popular in eastern Japan, in contrast to the kiulownia gray warm patches, which are mainly sold in western Japan, and both account for the majority of the market share of the Japanese warm patch market.
 
Mycoal is mainly responsible for the production of warm stickers, and the sales affairs are entrusted to ST Group, so Mycoal warm stickers are often called "ST chick warm stickers" in China. However, Mycoal's warm paste business has been gradually transferred to the ST Group, and the warm stickers currently sold by ST include new products under the Mycoal brand (マイコール) and ST (エステー), but they are actually produced by Mycoal.
 
Since 2015, the heating time of the regular version has been increased from 12 hours to 14 hours, although the heating time has been extended, it is still thin and lightweight, and does not significantly increase the feeling of weight and foreign bodies. At present, the general heating time of Japanese brands of light and thin heating stickers on the market is 12 hours, of which Mycoal and tung ash can reach 14 hours, while Chinese brand products are generally 10 hours.
 
In addition to the regular warm patches, foot patches and insole patches, Mycoal also has two specially designed warm patches for the shoulders and waist. The shoulder and waist stickers inherit the light and thin characteristics of Mycoal warm patches, which can be directly attached to the skin, using high-quality adhesives, which will not cause irritation to the skin, and adopt a three-piece split design, making full use of the elasticity of the warm patches to fit the body and not fall off easily.
 
In terms of price, Mycoal's basic warm stickers are 2 yuan per piece, and the foot stickers and shoulder stickers are about 3 yuan per piece, except for the insole stickers are about 9 yuan per piece, which is more expensive, and the overall cost performance is higher, but it can only be purchased through purchasing agents in China.