Shizuka Kawai

Known as Serenity Wheeler to western audiences, Shizuka is the long-lost sister of Katsuya Jounouchi. She was born with an eye defect that was causing her to go blind rapidly. During the Duelist Kingdom saga, her brother, with the help of Yugi and others, won three million yen (mistranslated as $3 million in the dub) to pay for a German doctor to perform an operation that would save Shizuka's eyes.