Kana once got asked by Sou and she answered that they do care about each other and just doesn't want to label their relationship. They also get into fights due to how they love each other SO much. They would argue about who liked first and talk about how they liked each other. They also don't want to have their relationship just to be strictly "professional". They also regularly visit each other IRL even when not doing a collab.

The cutest thing about them is that they call each other almost every night. Even when they're not talking and are busy with something else, they wouldn't hang the phone up and just keep it on call.