Shingo Sawatari/Relationship

Lackies
Similar to Jun Manjoume from GX, Shingo is admired by his friends. However, it is shown that they secretly get annoyed by his selfish attitude but don't seem to really care. When Shingo lost consciousness after his loss to Yūto, his friends took him to the hospital. They also admired his amazing second duel with Yūya due to his multiple Pendulum Summons

Reiji Akaba
Shingo is shown to greatly respect and admire Reiji's dueling abilities as shown when he bragged about how he was well known for his multiple summoning methods to Dennis. Reiji in return, is shown to have some faith in Shingo's abilities as shown by how he entrusted Shingo with the task of taking Yūya's Pendulum summons, had him test a Yosenju Pendulum deck, and had him become a Lancer to aide the others during the invasion by the Obelisk force. Reiji also taught Shingo how to Pendulum summon.

Yūya Sakaki
At first, due to his task of stealing Yūya's pendulum monsters as well as kidnap his friend to force him to duel in order to test them, Yūya hated Shingo. Shingo's defeat at Yūya's hands and losing the Pendulum cards caused Shingo to form a bitter rivalry with him. However, things changed during their second duel in which they both seemed to have gained great respect for each other. After generously offering to duel Yūya anytime the latter wanted, they appeared to have buried the past and became friends. Although their behaviors still seem to annoy each other, they still appear to be concern for each other in important scenarios such as when Yūya lost Yuzu and Shingo was defeated and captured by Security. Their common love for entertaining the crowed also helped improve their friendship which also allowed them to work well together in action duels.

Crow Hogan
When Crow and his gang saved Shingo and the other lancers form security, Shingo was grateful and thanked him. While Crow was weirded out by Shingo's rants about the Lancers and Standard dimension, he didn't seem to dislike Shingo. After Shingo defended Crow from a large Security guard while they were escaping, they seemed to have gained a lot of respect for each other as shown by their thumbs up signs.