I wrote it about a "LINE stamp" of NHN Japan before.
NHN Japan's LINE earns 300 million yen by a virtual goods
NHN Japan started sale of very pretty LINE Stamp today. It is "Doraemon"!
They are used in this way.
Of course these are sold in the countries except Japan, too. Doraemon is a popular character abroad. If you are a LINE user whom Doraemon likes, check these!