Miki’s story begins when her parents, Jin and Rumi, announce they are getting divorced and swapping spouses with another couple, the Matsuuras. They also are all going to live in the same house. 2 sets of parents and 2 teenagers, Miki and her new stepbrother Yuu.
Miki is horrified at the idea at first and even though her new stepbrother is incredibly cute, she doesn’t get along with him because he’s such a jerk to her.
Miki spends her time going to school, playing tennis, and hanging out with her best friend Meiko. Her best male friend, Ginta, is also close with her. When Yuu transfers to their school, Ginta starts to get jealous. He admits he has always liked Miki, even though he broke her heart in middle school when she confessed that she liked him.
Now torn between two guys, Miki doesn’t know who to like. Amidst her drama, it’s soon revealed that her best friend Meiko was having an affair with their teacher, Nachan Namura. Miki is shocked because Meiko never told her, and that makes Miki feel like Meiko doesn’t really like or trust her. Nachan resigns in scandal and moves to Hiroshima, leaving Meiko heartbroken. But Miki is there for her.
Miki spends most of the story being clueless and ditzy, crying at everything and desperately trying to get to know Yuu, but it’s hard, as Yuu is distant and doesn’t tell anyone anything personal.
Ginta competes for Miki’s affection, but it becomes clear that she only sees him as a friend, and he slowly gives up. But it’s OK, because he shares his pain with Yuu’s ex-girlfriend, Arimi, and the two of them eventually fall in love.
Eventually, Miki chooses Yuu and they begin to date. But in the seventh volume, Yuu does some digging in their parents’ past and discovers that his mom’s old boyfriend was Miki’s father Jin. Yuu already doubts his dad’s paternity, and now he assumes that he and Miki must be half-siblings, so he breaks up with Miki and goes to Kyoto Institute of Technology.
In the final volume, it is revealed that Yuu and Miki are not related, and they get back together.
Personality:
Miki is a typical shojo-character; that is, she is emotional, love-struck, whiny and she cries a lot. When confronted with a problem, her first reaction is either to cry or run away and cry.
She cares a lot about what others think, and doesn’t like other people gossiping about her. She can be short-tempered and jealous, gullible and stubborn.