Jam bread. ジャムパン。A type of kashi-pan, sweet buns or buns with sweet fillings ("kashi" means "confectionery").
Very simple: a bun filled with strawberry jam. First made in 1900 by Kimuraya on the Ginza. The original jam bread contained apricot jam (anzu). The bread is oval to distinguish it from the round anpan (buns filled with paste of azuki beans) also made at Kimuraya. Now various types of jam buns are available in convenience stores and supermarkets throughout Japan.