About
Haruka passed away one year prior to the events of the story, in a traffic accident. Before that, she donated blood to Maiko, who started seeing fragments of Haruka's memories after she recovered. Yukiya mentions that Haruka used to be a very spiritual person with mysterious powers that were passed on to her son, Touya.
Haruka was married to Seiya, Yukiya's twin brother, and didn't reciprocate Yukiya's feelings.