Seguchi Mika is Tohma's wife and Yuki's sister. She cares about Yuki a lot and is always dropping by to talk to him and advise him of certain things. She is one of the people who know about Yuki's past and advised Yuki about Shuichi. Yuki doesn't like her approaching him so often and telling him what to do. She's also tried to take Yuki back to their parents, since Yuki hasn't been back home for a while and has no intention to return. She is a woman with power and persuaded Shuichi to ask Yuki to return home. She as the ability to get Tohma to do almost anything for her, and she promised NG's full support if Shuichi did the favor. Oddly enough, she seems to be the dominant one in her relationship with Tohma.^-^

Aside from Yuki, Tohma is probably the other person that Mika cares the most about. Although Mika doesn't seem to come in much contact with Tohma, she cares about him a lot and doesn't mind Tohma's 'fondness' for Yuki. Mainly, Mika cares about Yuki and Tohma, and as long as nothing's troubling them, she's happy. :D With any sort of trouble, she will go out of her way to end sort it out as quickly and efficiently as possible. Mika drives a red car. ^-^