Shun Kurosaki/Relationship

Ruri Kurosaki
The two are siblings, and seeing from Shun's determination to find her, they had a close relationship. He goes as far as to target LDS in attempt to bargain Reiji Akaba for her. In the past, he shows his frustration as Ruri remains unfound.

Yūto
Shun and Yuto appear to know each other for along time. Although there have been disagreements and differences between their ideas, they have a lot of faith and trust in each other. Yuto refers to Shun as his best friend, protesting that the two did not 'run away' from their homeland, while Shun shows concern when Yuto fought with Yugo when a Synchro Summon was detected. Later he angrily asked Yuya what had happened to Yuto and accused him of doing something harm to him.

Yuya Sakaki
Shun has a complex relationship with Yuya. When they first met, Shun paid him no heed and ruthlessly Xyz summoned Rise Falcon to defeat the LDS people chasing him and seal them into cards. This act horrified Yuya for some time, causing him to temporarily gain a small degree of fear towards Shun. However, Shun later gains a large degree of, unwarranted, hatred and hostility towards Yuya when he discovers Yuya has possession of Yuto's Dark Rebellion Xyz Dragon card. This made him initially believe Yuya had caused Yuto's disappearance and stole the card as seen when they interacted at the tournament and again when he learned Yuto's duel disk was used as reference for inter-dimensional travel technology needed to travel to the Synchro Dimension, and accused him of stealing it as well. It was only after Yuto's spirit contacted Shun from within Yuya after this accusation and told him to trust Yuya did Shun relent on his impatient and rash behavior towards him.

Reiji Akaba
Despite previously being opposing forces, they team up for their own gains. Shun had hoped to bargain Reiji for Ruri, but ended up joining LDS to find more opportunities to find Ruri. In turn, Reiji has informed Shun on what his father is up to. The two share a common goal, to find Reo Akaba and know what he is up to.