Celeste

Sakura, aka Celeste, is an angel and the younger sister to Aphrodite. Prior to the series, Celeste participated in a battle between the angels and devils. She soon fell to the Human World after trying to defeat the devil, Uragano, and lost her memory as a result. She then met a photographer named Shouichirou Hanasaki. He cared for her while she was still recovering from the battle and they soon fell in love and got married. Three years later, after Momoko was born, Celeste, who had taken the name Sakura, regained her memories as an angel and had to return to the Angel World. She left behind her ring, which had been part of the Saint Something Four. Another few years later, she returns and explains to her daughter why she had left.