Ayato Matsumae was the deceased husband of Satsuki Matsumae and father of Ohana Matsumae. A professional photographer, he first encountered Satsuki during her teenage years while she faced conflict with her mother, Sui Shijima, at the Kissuiso hot spring inn. Their meeting occurred when Ayato photographed Satsuki at a swimming pool, capturing her vulnerability and rebellion. This moment left a significant impression on Satsuki, deeply affected by Ayato's perspective through his lens.

Living in Tokyo, Ayato played a pivotal role in inspiring Satsuki to pursue her ambitions beyond Kissuiso, encouraging her dream of becoming an editor. He provided both emotional support and creative motivation. Despite their age difference—Ayato an adult, Satsuki still in high school—their relationship developed romantically. Satsuki openly confessed her feelings and kissed him, an action that surprised and endeared her to him. They married and moved to Tokyo together.

Ayato chose the name "Ohana" for their daughter, deriving it from the Hawaiian word for "family," symbolizing his values regarding familial bonds. He died approximately fifteen years before the series' main events, leaving Satsuki to raise Ohana alone. His death profoundly impacted Satsuki, who resolved to honor his memory through dedicated motherhood and her career, rejecting reliance on her estranged mother. This resolve solidified when she visited Kissuiso with infant Ohana shortly after Ayato's passing; witnessing Sui's resilience managing the inn alone after her own husband's death reinforced Satsuki's commitment to independence and strength.

Ayato's legacy endures in Ohana's inherited curly hair and Satsuki's lasting devotion to their family. His early encouragement directly shaped Satsuki's career path as an editor in Tokyo.