Kashiwa mochi is a steamed mochi (sticky rice cake) filled with sweet red bean paste and rolled in an oak leaf. It's especially served on children day 'Kodomo-No-Hi' and boys day 'Tango-No-Sekku' both celabrated on the 5th of May.
Sakura mochi is close to the kashiwa mochi with a pink paste and is rolled in a cherry tree leaf. It is served in spring under the cherry blossom.