Zachary Powers, meet Capricorn Anderson. Cap just transferred here
The reason this is super important in the story is because this is the reason why he gets arrested and has to take Rain to the hospital where they meet Mrs. Donnelly. All because of this scene is the reason the story is what it is. Also the title is named after what happened with Rain.
In the story she gets reminded of her life in Garland after looking at Cap with the long hair and beads. Which she then makes Cap come home with her. This is important because when he has to come home with her he is forced to go to a public school which is the main point of the story.
Near the end of the chapter, Zach meets Cap and shows him around the place. He also wants Cap to be the 8th grade president so the school can make fun of him. This introduces Zachary and his main goal (To make fun of the 8th grade president). This also shows how Zach is very churlish.