Shuichi Iguchi/Relationships

Stain
Spinner has complete and total respect for the hero killer. It was Stain's words that inspired Spinner to become a villain and join the League of Villains. As a sign of his appreciation for the hero killer, Spinner made his villain costume very similar to that of Stain.

Following Stain's incarceration, Spinner has taken it upon himself to continue Stain's quest to rid the world of false heroes. He openly states that the League of Villains keep Stain's principles in mind when planning to kill someone.

Tomura Shigaraki
At first, Spinner joined the League of Villains thinking that it would help him to continue with Stain's legacy, so he had no problem with Tomura, following his orders without questioning them.

However, as the time progressed, Spinner began to have doubts about Shigaraki's actions. The first clue is when the League attack a police convoy to get at Overhaul, who was arrested. Spinner isn't happy about attacking police officers, who have nothing to do with creating a true society. Tomura Shigaraki reassures Shuichi that it is a necessary sacrifice.

Later, after the League had little benefit from other operations, Spinner finally loses his patience and begins to shout at Tomura that he has little faith in him and his ability to lead the League of Villains. He has openly questioned how Tomura and the League will help him bring Stain's goals to fruition.

Nevertheless, he still respects Tomura and was amazed by his determination to defeat and tame Gigantomachia. He also made an attempt to rescue him from the subordinates of the Meta Liberation Army and Re-Destro. However, he is left in awe at Tomura's victory and the enemy bestowing an army upon him.

Mr. Compress even goes as far as to claim that Spinner is the closest and most devoted of Tomura's followers.

After the prison break at Tartarus, Spinner reveals that him and Tomura had bonded over video games, and also realizes that his leader is being controlled by someone else. He then asks who is in his leader's body, saying that he isn't the one he chose to follow, showing his realization that Tomura isn't himself.

Himiko Toga
Both Spinner and Himiko came to the League being affected by Stain, however Spinner follows his ideals, while Himiko loves Stain in her twisted way and wants to 'become' him.

During their over a month-long battle with Gigantomachia, Spinner reflects on how the League no longer aligns with Stain's ideology. He questions Himiko on why she is still with the League. She responds that she still loves Stain, Izuku Midoriya and Ochaco Uraraka too and that she wants to 'become' them. Spinner notes how carefree she is and how nice it must be to have a reason to live.

During the Paranormal Liberation War, Spinner stops Himiko from blindly going into the battlefield, telling Himiko that he believes himself and the others to be nothing and that they are strays that just happened to find one another, but she isn't the only one upset about Twice's death. He reminds her that their group was what Twice considered a family, and Tomura would probably like to see them all together. He says that their brand as the Paranormal Liberation Front is to let folks do as they want, but she should come back to them quickly. Himiko smiles at him in gratitude.

Their bond as a group is later shown when All For One in Tomura's body commands the Nomu to retreat, taking only Spinner (with Dabi and Skeptic in his scarf), only for Spinner to question that decision, saying that Mr. Compress and Gigantomachia shouldn't be left behind and that Toga hasn't returned yet, knowing that it's something Tomura wouldn't want to happen, only to be turned down by the annoyed All For One.

Dabi
Dabi and Spinner share similar interests in taking down the hero society as both are huge followers of Stain's ideology. However, Dabi seems to disregard Spinner's presence like with most of his fellow League members. He even complains about Spinner's driving skills to the point the latter would shout back with annoyance.

Dabi often snarks at Spinner's expense and insults him whenever the opportunity comes by. When Spinner later reveals his motivations for joining the League of Villains to Tomura, Dabi mocked him by calling him a hollow cosplayer, implying that the latter enjoys insulting Spinner for laughs.

Spinner was quite surprised to learn Dabi was the son of Endeavor, remarking on how he did not talk about it.

Mr. Compress
Spinner and Mr. Compress appear to be on good terms, though they rarely interact with each other. Mr. Compress is also included in the same regiment of the Paranormal Liberation Front as him.

During the Paranormal Liberation War, Mr. Compress tried to stop Himiko from jumping off Gigantomachia and Spinner then proclaimed that the League is like a family, so she should return to them, to which Atsuhiro didn't object. Later, Compress calls Spinner quite officially, as an associate, but later admits that he actually loves the League. He also understands that Spinner is a much closer follower of Tomura than him and entrusts him with waking Tomura up.

Spinner was also reluctant to the idea of leaving him behind, as he and All For One in Tomura's body were making their escape.

Magne
Spinner and Magne teamed up during Vanguard Action Squad Invasion, despite their difference of opinions. Magne wanted to just kill without rhyme or reason, while Spinner thought it important to think about who to kill and who to spare in accordance with Stain's code of conduct. Their different mentalities and ideologies clashes when Magne tries to kill Izuku, being stopped by Spinner, since Stain saved Izuku's life, and therefore he considers him worthy to become a hero, a decision that Spinner wants to respect.

After they were subdued by Mandalay and Tiger, Magne blamed Spinner for their defeats.

Re-Destro
Spinner barely shows any interaction with him, but he and Re-Destro coined the organization's name together and seeing his submissive nature towards Tomura, he believes that he became a CEO by serving higher-ups the same way he serves Tomura.

Trumpet
During the Revival Celebration, Spinner viewed Trumpet as someone irresponsible for being on the front lines while having a supportive role in battle. He compared the Liberation Army's executive to himself, which made Trumpet annoyed.

However, after the League and Liberation Army merged, Spinner no longer views him as an enemy, but barely interacts with him.

Izuku Midoriya
Due to Stain not only sparing, but saving Izuku, Spinner has total respect for Izuku and his potential as a future hero. Spinner even went as far as to protect Izuku from being attacked by his fellow villain, Magne, just because he so deeply believes in Stain’s ideology.