Midori Mine

Kouichi's sister,three years older than him.She's in college. Opposite to his brother,Midori's a very cheerful and outgoing person,but also very clumsy.Even though her intentions are always the best,she ends up getting herself in trouble,being totally clueless;which makes Kouchi and her boyfriend to help her all the time. She calls him"Little Kouchi" and develops a tight bond with Keito,because of the similarities between the two of them. in the end of the series, 3 years later, she's shown to have married her college's boyfriend and to have had a son with him.