Hishi mochi

Hishi mochi (菱餅 / ひしもち) is a symbolic Japanese sweet associated with the Hinamatsuri "Girl's Day" festival, which coincides with the calendar date for Xiuxi (上巳). The sweet is diamond shaped and typically formed from three layers of red (pink), white, and green mochi, from top to bottom. Depending on region, red may be substituted for yellow, or the sweet may have 5 or 7 layers instead. It is usually presented with hina dolls. The shape is believed to have originated in the Edo period, and to be a representation of fertility.

Description: Wikipedia — Hishi mochi, CC BY-SA 4.0