Midorikawa Retasu
From Kokorodatabase
A canon character that rarely appears because she used to have a crush on Shirogane Ryou. While she is currently over her crush on the Shirogane and desires nothing more than to be on a good footing with him again, she still doesn't appear too often because her son from Chrono, Kyr is still over-protective of her and desires that Ryou and Retasu should have nothing to do with the other.
Currently, she is dating an original character, Kitano Kouki (the younger brother of Kitano Shinrai), as her other canon character relationships have not worked out.