Hoshikawa Yorozu Sanrei Soushi

In a place called Hoshikawa, ancient trees can host spirits that sometimes take human form and live among people, even marrying them. Their descendants inherit unique abilities from their spirit lineage. Once numerous, only one tree spirit remains—Hoozuki, who married a man named Tenma, who later left and did not return. She stayed and was watched over by her descendants, who in turn protected her. Five generations later, one of her descendants is a teenage boy named Kazuho, whom she has raised. As he grows older, he begins to develop feelings for her, though he must contend with the lingering presence of her past husband.