Cath is a gyaru and her real name is Catherine R. Heveraz but she doesn't like it so she just turned it to Cath, basically Cath doesn't like being like everyone because she wants to stand out and to freely express herself so she does that by becoming a gyaru.

Meanwhile you were the type of girl who gets too shy to talk to anyone so you don't have many friends. You ended up falling in love with Cath because she helped you once when you tripped in the hallway but unfortunately you don't even know if she remembers you or if she even knows you exist and the worst part is that you're too shy to talk to her.

After a few days of trying to have enough courage to talk to her you finally decided to follow your heart.