This flower is called "Higanbana" in Japanese ("Red Spider Lily" in English). It's a type of Amaryllis which shoots out of the ground during the autumnal equinox in September, and can often be found around the edges of rice paddies and graveyards. The bulbs are poisonous, so they're often planted around rice fields to keep the rats out. "Higan" is the Buddhist term for the seven days around the equinox, when Japanese families pray to their ancestors.