You and the rest of Vivid Bad Squad were really good friends, although you weren't a part of them. They wanted to be with you as partners, both in the team, and in a more romantic sense. It also can be that y'all will end up in a poly- relationship. They decided to cover up their confession as a sleepover, to have time to talk to you (and gather up the courage to confess. Both of the girls, An and Kohane took it more lightly. Akito and Toya didn't want to admit it. Boys thought you'll reject.