Tomomi Aizawa is a schoolgirl who, after visiting the Pia Carrot restaurant with friends and admiring the beautiful, elegant waitress uniforms, becomes determined to work there. Her lack of experience initially poses a challenge to gaining employment. She first appears as a playable character in the consumer versions (Sega Saturn and Dreamcast) of "Welcome to Pia Carrot!! 2". Her story continues in "Welcome to Pia Carrot!! 2.2" on Game Boy Color, set four months after the events of "Pia Carrot!! 2". Tomomi takes on increased responsibilities in "Welcome to Pia Carrot!! 3" and its Game Boy Advance version "3.3", working as a waitress at Pia Carrot 4th, where she engages with protagonist Akihiko Kannaduki (younger brother of Shiho Kannaduki from the first game) and staff members Sayaka Takai, Akemi Hasegawa, Mina Hinomori, and Tsukasa Enomoto.

Physically, Tomomi sports brown short hair, violet eyes, and a pale complexion, often seen wearing a kemonomimi headband, a skirt, and knee-high socks. She maintains close bonds with fellow waitresses Yuki Kamizuka and Noriko Shima throughout these games. Tomomi also makes an appearance in the 2002 anime film "Welcome to Pia Carrot!! - Sayaka's Love Story".