These are Japanese anemones (Eriocapitella hupehensis). Their yellow and green flower centers, surrounded by white petals, emerged from the darkness before dawn.
On workdays, I usually get up around 5:00 a.m. This is fine in the summer, but it's too early in autumn and winter for a morning walk and photography. In late October, the sunrise in Tokyo is around 5:50 a.m.