Ihabu no Seikatsu

There were once two women who loved each other: Mary and Eli. When having a child, they decided that Eli would provide the egg, playing the role of father, while Mary would give birth, playing the role of a mother. But when the child they had worked so hard for was born a boy, they couldn't help but be disappointed. Eventually, Eli abandoned their family, leaving Mary to raise Ichabod, their "greatest failure," alone.