Ryuji Korekuni Edit
Tomohisa & Ryuji are best friends, and it is shown that the two met at a party when the Tomohisa snuck out and found Ryuji is building a snowman, Tomohisa blushed when he saw Ryuji. The two are very close, something commented on often in interviews and by Tsubasa. They joined Bambi when they were older and became a two person unit called Kitakore. The two live together.
When Ryuji was being bullied, Tomohisa would defend him alongside with Yuta Ashu.
Tomohisa thinks Ryuji is cute and handsome, but more importantly has a bright smile that can light up any situation. He enjoys teasing Ryuji, usually over his reactions to things and people. He listens closely to Ryuji, especially when he mentions things he would like to get and can sometimes get carried away with getting them for him, leading to Ryuji telling him to tone it down though he does appreciate that he cares.
Ryuji has taught Tomohisa how to do more chores and cooking, something Tomohisa greatly appreciates. Tomohisa wants to support and protect Ryuji because of how much he's struggled growing up and because of his family life, though Ryuji wishes he wouldn't worry so much about him now that their older. When Ryuji has a hard time with solo work, Tomohisa will keep messaging him on JOIN so he feels better and often lets him sleep or lean against him when he's tired. Tsubasa once commented that Ryuji seems to feel better at the sound of Tomohisa's voice, something Tomohisa said makes him happy if it turned out to be true.
Ryuji once said there was no other partner for him but Tomohisa, which made him happy to hear. Tomohisa has said that him and Ryuij are destined partners.
Kazuna Masunaga Edit
Tomohisa cares about Kazuna, and it is shown that the two were in the same company business as reporters when they were younger.
At some point, their relationship became strained because of Kazuna withdrawing himself, which Tomohisa didn't understand but tried not to push it. Kazuna still liked and admired his friend, but started to grow jealous over Tomohisa's talents and bright light he gave off. Tomohisa often tried to reach out and had moments where their relationship seemed to move forward only for Kazuna to withdraw again.
The two rekindle their relationship later in the anime, when Kazuna lets out his frustrations and opens up about how he's felt all this time along with having to search for his mother and doesn't feel like he can do that because Tomohisa out shines him. Tomohisa reassures Kazuna that he had his own bright light, and that together with the rest of B-PROJECT, his mother will be able to find him again. Their relationship slowly starts to mend afterwards.
Tsubasa Sumisora Edit
Tomohisa treats Tsubasa differently than everyone else, giving her kindness and respect. He teases her sometimes, finding her reactions cute and sometimes opens up to her about his relationship with Ryuji though he doesn't go into detail about it. Tsubasa admires Kitakore's relationship.