ていうか微妙に黒髪じゃないのね
http://www.web-marmalade.com/products/b-couple/img/character/rena-char4.png
http://www.web-marmalade.com/products/b-couple/img/character/akiha-char5.png
http://www.web-marmalade.com/products/b-couple/img/character/rin-char4.png
http://www.web-marmalade.com/products/b-couple/img/character/fren-char4.png