At the beginning of the book Kira-Kira, the two main characters, Katie and Lynn were very closed. But as time goes by, the two girls both grew up and they like different things so they didn't be close to each other anymore. But they still wanted to be close to each other, so when Sammy needed both of their help, they worked together quickly. But Lynn was too weak at that time that she couldn't go ask for help, so Katie went and asked for help by herself. After that, the two girls got close again, but their relationship had became different from before. Before the accident, Katie needed Lynn's help to do most things. But after the accident, Katie was on her own, she can do many things only by herself, she doesn't rely on Lynn anymore.