The flower in the background is similar to a white chysanthemum.
From Wikipedia:
„In some countries of Europe incurved chrysanthemums are symbolic of death and are used only for funerals or on graves, while other types carry no such symbolism; similarly, in China, Japan and Korea, white chrysanthemums are symbolic of lamentation and/or grief.“
*raises death-flag for Hinami even higher*
Fortunately, I think it’s a clover flower to go with the clovers that are also there…