Little is known of the boys, though all are seen playing Jenga with each other in "Bee My Baby," showing they get along well. All of them enjoy eating taffy and turkey. One brother is taught math by babysitter Happy. Two of them appear in the crowd waiting to get a copy of Raspberry Shortcake Space Attack V in "Dang It Feels Good to Be a Gamester."
Gwen's baby brother is the focal point of "Bee My Baby," roaming all around San Francisco while Bessie and Penny chase after him. He later appears in "Woodward and Beesting" when Bessie tries to learn what Portia's secret is through him, an attempt that fails.
In "Apoxalypse Now," all except one brother have the chicken pox, with Gwen expressing annoyance she has to share the disease with her brothers. Bessie sneaks into the Wu residence and tries to infect herself with chicken pox by getting in close contact with the boys.
Gwen's brothers (save for the baby) make their final appearances in "Children of the Unicorn," where they don't believe their sister saw a unicorn despite Gwen insisting she did.
Gwen's Brothers are all Chinese-Americans and each of them have blue eyes and black hair. The two oldest have spiky and long hair, respectively. The spiky haired brother wears a blue shirt with white sleeves, green cargo pants and black and white sneakers. The long-haired one sports a yellow shirt with a green stripe, blue pants and brown shoes.
The middle siblings both have short hair. One has a teal t-shirt, gray shorts and black and white shoes, while the other has an outfit consisting of a red t-shirt with orange stripes, blue jeans and brown shoes with white soles.
Gwen's baby brother, being an infant, wears nothing except for a white diaper. He has one tooth sticking out, showing he has begun teething.
- The majority of them only speak in "Bee My Baby." The baby is the sole Wu brother who has more than one speaking role.