Yumika

The eldest daughter, Yumika is the strongest mahjong player of the three sisters. Smart and sexy, Yumika is a careful player, practically unbeatable until bested by the protagonist. She's seeking a husband who will support her ambitious goals as a sophisticated businesswoman.

Following Rumi's abduction, Yumika joins the rescue mission. She has her reservations about being too noisy into other people's business but the others disregard her warnings. When it becomes evident to her who has taken Rumi, she remains silent, waiting to see how everything turns out before passing judgement upon others.