An-pan was invented by Yasubei Kimura[木村安兵衛（きむらやすべい）] who ran a bakery, Kimuraya[木村屋（きむらや）] and his son, Eizaburō[英三郎（えいざぶろう）] in 1874. An-pan which was blended with bread from Europe and Wagashi[和菓子（わがし）](Japanese confectionery) was an epoch-making invention. And this is also the origin of Kashi-pan in Japan.
This An-pan was presented to Emperor Meiji[明治天皇（めいじてんのう）] and he liked this and this came to be delivered to him. After that, An-pan became widely recognized and that became one of representative Japanese breads. Even now, An-pan of Kimuraya is popular.
Typical An-pan is divided into two types; Tsubu-an-pan[粒（つぶ）あんパン] and Koshi-an-pan[こしあんぱん].
Tsubu-an-pan is an An-pan filled with Tsubu-an which is non-mash Anko and Koshian-an-pan is an An-pan filled with Koshi-an which is mashed Anko.
Commonly, both of two are sold in the bakery which makes An-pan because of the differences of customer's preference. Sometimes, black sesame is put on Tsubu-an-pan and poppy seeds are put on Koshi-an-pan because of discerning the filling. And sometimes a salted Sakura blossom is also put on An-pan.
Other than those, there are some kinds of An-pan such as Shiro-an-pan[白（しろ）あんパン] and Uguisu-an-pan[ウグイスあんパン].
Shiro-an-pan is an An-pan filled with sweetened white kidney bean paste and Uguisu-an-pan is an An-pan filled with Uguisu-an which is a sweetened green pea paste.