Miu Shiun'in

Miu Shiun'in (紫雲院 美宇 Shiun'in Miu) is a character in Yu-Gi-Oh! ARC-V manga series. She is the younger sister of Sora Shiun'in.

Past
According to Sora, Miu was his only family. Miu had a weak sickly body and was hospitalised as the result. Sora would often visit her at the hospital, trying his best to cheer her up. While Sora tried to remain optimistic that she will heal one day, Miu knew that she wouldn't live long and urged Sora to see the world in her place. She eventually succumbed to her illness and passed away. Sora, who was distraught by her death, was chosen by G.O.D and was allowed to repeat his life with her. Unfortunately, no matter how many lives he had repeated, he still couldn't cure her illness even with future medication. Aware of G.O.D's power to create countless parallel worlds, Sora made it his goal to restore G.O.D's true power and create a world where he and Miu can live together.

Yūya & Yūri vs. Sora
During Sora's Duel against Yūya, Sora purposely threw his photo with Miu for Yūya to see and made up a sob story that Reiji has taken her as a hostage and the president threatened to kill her if he doesn't capture Yūya, so the Phantom will sympathized and allow Sora to win. This plan unfortunately was foiled by Yūri who was easily able to see through his lie and then ripped the photo once Sora admitted this. The photo itself turned out to be a switch for a trap that will work once the photo was destroyed as a countermeasure in case his lie was exposed.

Dream
After Sora was defeated by Yūya, losing his consciousness in the process, he was saved by Ren. While he was unconscious, Miu appeared in his dream, telling Sora to wake up and asking if Sora has forgotten about her, which Sora answered that he hasn't and he will never forget about her.