When Betty died, Tadase at first believed that it was Ikuto Tsukiyomi who killed her by hearing his music. This was because Ikuto had been standing over Betty's body with his violin when Tadase found her dead. However, in Chapter 38, it was revealed that Betty had died of old age and that Ikuto had been playing his violin as a tribute to her death. In manga Tadase hears this information from his grandmother, but in anime he and Amu Hinamori were inside Ikuto's memory and saw what had happened.
- Tadase Hotori: Tadase owned Betty and loved her a lot. They were close friends before she died. In the first episode of Shugo Chara!, Amu Hinamori confessed her love to Tadase, but he turned her down because there was already someone he liked, who turned out to be Betty. That meant that even after she had died, Tadase still cared for her.
- Ikuto Tsukiyomi: Ikuto may have known Betty because he was friends with Tadase during his childhood. He said goodbye to Betty when he found her dead and made a tribute to her by playing his violin.
- It is possible that Utau Hoshina may have known Betty too, seeing as, like Ikuto, she was also friends with Tadase when he was younger.
- In a Q&A segment, in the final volume (12), Betty is proven to be a Afghan Hound.