彼岸花开忘河川彼岸花落恋河川
[bĭ àn huā kāi wàng hé chuān bĭ àn huā luò liàn hé chuān]
This username originates from mythology about the afterlife where the red Spider Lilies (彼岸花) grow along the river crossing to Hades. This sentence expresses memories or yearning of a lost romance by linking its prosperity with the flow of rivers in netherworld myth.