Logan Bruno is described as to have blond hair and a thick, southern accent. He lives with his brother and sister and parents, and has a cousin named Lewis who dates Dawn. Logan is Mary Anne Spier's boyfriend. He was born in Louisville, Kentucky and moved with his family to Stoneybrook when he was 13. His address throughout the series is 689 Burnt Hill Road. Mary Anne fell in love with him because he looked like Cam Geary (her favorite movie star).
Logan declined regular membership in the club because he didn't want it to conflict with his sports but he stayed on as an associate member to take jobs when no one else was available. He babysits for his younger brother and sister often. He works as a busboy at the Rosebud Cafe. Logan also briefly joined a gang at SMS before realizing how much that could hurt him.
At Camp Mohawk, Logan earns a Hiawatha badge which means that he can do any water sport. In Book 109, Logan's father decides that he should go to his old boarding school, Covant, but with Mary Anne's help, Logan is able to persuade him not to make him go.
Logan and Mary Anne briefly break up from Mary Anne Vs. Logan, but reunite in Mary Anne misses Logan when they work together on a project for authors day, along with Cokie Mason and Pete Black.