In the stamp, familiar characters who have consistently decorated the package since the release of Umaibo will appear in various costumes. Umaibo is celebrating its 35th anniversary this year, but it is said that there is no official name for the character yet. However, it seems that he will play an active part by taking advantage of the characteristic of "cosplay lover" which is the only setting in the stamp.
Yaokin is currently selling "Premium Umaibo" for 20 yen each to liven up the 35th anniversary of the release of Umaibo.