Eventually Persephone had to divide the year between her mother and her husband similarly to what Leewon was doing in Roses and Kiss- spending his time with Caesar and then going back to his father for some time
Because of Hades’ trick Persephone half-willingly, half-forcibly stayed with her husband, just like Leewon with Caesar. Both Persephone and Leewon became tied to the underworld and the God of Death forever.