Although she was distant to her father, Mariko was very close to her grandfather. She had very few friends as a child, mainly Kenuicho Harada and Yukio. Her father engaged her for marriage to the minister of justice, Noboru Mori. After learning that she was to be the heir to the Yashida fortune, Mariko attempted to kill herself, only to be stopped by Logan, the Wolverine. Logan then proceeded to rescue her from the Yakuza once, but the second time he was unsuccessful. Taken to her father, Mariko was surprised when Lord Shingen tried to kill her. However, she was once again taken, this time to her grandfather. Shocked to see the monster her grandfather had become, at the Battle of Yashida Tower, Mariko helped Logan kill the man. Soon after, she was elected the new CEO of Yashida Corporation.