Kureno Sohma/Relationships

Arisa Uotani
Kureno first met Arisa when he went to the store that she was working at, at the time. After they met, they could not stop thinking about each other. Arisa finally saw him walking by and talked with him, then he took her out for a meal. However, torn between his growing feelings for Arisa and his loyalty to Akito, he initially decided to not contact her anymore, despite him really wanting to be by the side of the first person from "the outside" that he properly could interact with.

Arisa and Kureno had a slow-moving relationship through the manga, but at the end of the story, they move away to the country-side and live together.

Tohru Honda
Kureno and Tohru are said to resemble one another a lot, personality wise. Kureno comes to trust Tohru so much that she's the first person he willingly tells many secrets to: that he loved Arisa despite not being able to meet her anymore, that his own curse had been broken, and that Akito is a woman rather than a man.

Akito Sohma
Akito was Kureno's initial crush before Arisa. He used to spend a lot of time with Akito when they were kids and continued to do so as adults, with him as basically her right hand. The main reason why Kureno stayed with Akito was a mix of affection and (majorly) pity, especially since his curse was broken before anyone else's and in front of her, which mentally and emotionally broke her. However, he eventually realised that by never really telling Akito "no", he ended up hurting the two of them and especially her.

Unlike the rest of his family, Kureno suffers the least amount of violence from Akito. Even when Akito stabbed him, he forgave her and she went to get help for him.

Shigure Sohma
As children, Shigure and Kureno had a pleasant relationship. Kureno looked up to Shigure and followed him around and Shigure indulged him like a big brother.

In the present, however, Shigure heavily envies and resents Kureno because Akito chose Kureno over him. He also knew that Kureno's curse had been broken, but kept quiet about it probably for Akito's sake. Kureno, however, still cares for Shigure and shows the hatred was one-sided, treating him with respect and politeness. Over the phone, Shigure also tells Kureno about his feelings for Akito, despite his hatred for Kureno. Even despite his resentment, Shigure was clearly very shocked and even concerned when he learned Akito stabbed Kureno and was clearly affected considerably by the incident, showing that even with his resentment and jealousy, he never wanted the man dead and there was a part of him that still cared for Kureno.

Momiji Sohma
Momiji sends Cinderella-ish DVD to Kureno so he can watch.

Hatori and Ayame
Kureno interacted with both of them before his curse was broken, when they were all still young children. Kureno is a few years younger than Shigure, Hatori, and Ayame, but he was old enough to also have the dream they all did and to remember the experience. They are also the four members of the zodiac who know that Akito was born a girl. So Kureno shares a relationship with Hatori, Ayame and Shigure through that particular knowledge and experience that no one else but them has.

Isuzu "Rin" Sohma
Isuzu Sohma is rather cold to Kureno, and explicitly says it's because he is close to Akito and because he feels like an outsider. Unbeknownst to her, the latter part comes from him not being cursed any longer.

Later, Rin saw Kureno talking to Tohru from a distance. Since Tohru fell into a dazed, tearful state after what Kureno told him, Rin wanted to confront him on whatever he told her (she couldn't hear their talk due to the distance), but in her way to his quarters she was caught by Ren Sohma, tricked into getting Akito's treasure, and then caught by Akito and confined to the Cat's Room. Some time later, Kureno found out about her imprisonment from a maid who was tasked with watching over her and, despite knowing that Akito was behind everything, disobeyed her for the first time and took Rin out of the Room and into the Sohma hospital.