The 1-cent Z-grill stamp will go on sale on June 14, along with 99 other top stamps in Gross’ collection. The entire collection is expected to generate between $15 million and $20 million.

Japan Post will issue the first new 1-yen (1 cent) postage stamp in 70 years on April 14, featuring its bear mascot character, Posukuma. The mascot’s name combines the Japanese word “kuma ...