Number 6/Relationships

Knuckleduster
Number 6 has great respect for Knuckleduster when he was the hero O'Clock, to the point that he has a huge poster of him in his apartment. When he was still an experiment he watched when O'Clock's career fell apart and lost his Quirk. His admiration is such that his characteristic scar on his face is self-inflicted, as a tribute to the one that Knuckleduster has. He is so proud of this scar that he can not bear to have another injury on his face. His goal is to become the true successor to O'Clock, considering multiple possible names for himself, including: "O'Clock II" or "Two O'Clock".

Knuckleduster had no relations with him before investigating the Villain Factory. He doesn't know who he is or what his origin is, except that he is an agent of the Villain Factory and that he is in possession of his stolen Quirk, Overclock. When they finally meet in person, Knuckleduster considers him nothing more than a villain, one that he plans to eliminate, so when Number 6 asks him to recognize him as his successor he flatly refuses. Despite being enemies, and having no qualms about killing him, Number 6 considers Knuckleduster the best one, much better than the Pro Heroes, even All Might.

After his rejection from Knuckleduster, Number 6 frequently starts to hallucinate his own idealized version of O'Clock to communicate with, one who acts as the "master" he so desired; watching over him, and providing him with support and advice.

Koichi Haimawari
Although they have never met in person before, having been responsible for the Next-Level Villains attacks, Number 6 knows very well who Koichi is, despising him but not taking him as a threat to their plans. He also knows about Koichi's relationship with Knuckleduster; and in a way, it is implied that he feels somewhat jealous of Koichi due to being Knuckleduster's disciple. This, coupled with the fact that he helped to ruin his plan to kill Captain Celebrity, caused Number 6 to start despising him.

Years later, posing as the manager of the Feather HATS, Number 6 spied on him and Kazuho, and devised a plan to gain fame as a hero as well to destroy Koichi physically, mentally, and socially. She tricked Kazuho into becoming the host of the new Queen Bee, causing her to face Koichi. Number 6 planned to frame Koichi in order for the tale of his Hero persona O'Clock II to become popular, only to be foiled by underestimating Koichi's Slide and Glide Quirk. As a result, Number 6 is indirectly charred by Endeavor's flames while Koichi escapes via flying after saving Kazuho, and 6 calls him a cheating bastard as he gets burnt.

This made Number 6 hate Koichi even more. After surviving the flames, Number 6 proceeds to then follow and talk to Koichi on a rooftop, where he explains his past as a "creation" and how he doesn't have a clue to what he is. He proceeds to state that while his body is fake, his rage and anger towards Koichi is genuine and real. Number 6 rants about how Koichi is garbage that only ruins other people's dreams, and swears revenge on him and Kazuho for ruining his plan, with the intention of killing them both for good so that he can re-start his life fresh without them.

Kazuho Haneyama
When posing as Rokuro Nomura, the manager of FeatherHATS, Number 6 begins to relate to Kazuho, ​​first on a purely professional level and then on a more personal one. Although initially Number 6 only did it to watch over and spy on Knuckleduster's allies and to meet his own goals, he developed feelings for Kazuho. Number 6 crafted Rokuro's personality to be supportive, kind and caring towards Kazuho, in order to get her to like him, and when he thought the time was right, he confessed his feelings to her, yet Kazuho kindly rejected them.

He takes Kazuho's rejection pretty hard, and for the next time he met Kazuho again, he lured her into an abandoned building to be parasitized by the Queen Bee, transforming into the villain Bee☆Pop. At this point, Number 6 only sees Kazuho as another tool to achieve his plans to gain fame as the hero O'Clock II, not caring about sacrificing her life to achieve his goals.

Endeavor
The Flame Hero was deployed to stop the battle between Bee☆Pop and The Crawler, which was secretly incited by the fake pro. Fearing his powerful reputation, Number 6 hid himself away from Endeavor. Unaware of Number 6's presence, Endeavor accidentally gave the villain severe disfigurement in Hellflame's crossfire. Despite this, Number 6 is indifferent towards Endeavor, consumed by his vendetta for the Crawler instead.