Giant crinum lilies (Crinum asiaticum) are native to tropical and eastern Asia and can be found in mainly the southern half of Japan, producing white flowers in summer. As you can see from the flower shape, the lilies are in the Amaryllidaceae family, the same as red spider lilies and so are toxic in their entirety. The thin orangish things on the flower are stamens.
Giant crinum lilies have been loved by Japanese people for so long that the Man'yōshū, i.e., the oldest extant collection of Japanese waka (poetry in Classical Japanese) compiled during the Nara period (710 to 794), includes a waka about the lilies. More than ten municipalities in Japan have designated the lilies as their flower.