Shizuku Tsukishima (月島 雫, Tsukishima Shizuku): A 14-year-old junior high school student who loves books.
Original Cast: Yōko Honna
Disney English Dub: Brittany Snow
Seiji Amasawa (天沢 聖司, Amasawa Seiji): An aspiring violin maker who attends the same school as Shizuku.
Original Cast: Issei Takahashi
Disney English Dub: David Gallagher
Asako Tsukishima (月島 朝子, Tsukishima Asako): Graduate student. Shizuku and Shiho's mother and Seiya's wife.
Original Cast: Shigeru Muroi
Disney English Dub: Jean Smart
Seiya Tsukishima (月島 靖也, Tsukishima Seiya): Librarian. Shizuku and Shiho's father and Asako's husband.
Original Cast: Takashi Tachibana
Disney English Dub: James Sikking
Baron Humbert von Gikkingen (フンベルト・フォン・ジッキンゲン男爵, Funberuto fon Jikkingen danshaku): An anthropomorphic cat statue from Germany belonging to Shirō Nishi.
Original Cast: Shigeru Tsuyuguchi
Disney English Dub: Cary Elwes
Shirō Nishi (西 司朗, Nishi Shirō): Owner of a local antique shop. Seiji's grandfather
Original Cast: Keiju Kobayashi
Disney English Dub: Harold Gould
Yūko Harada (原田 夕子, Harada Yūko): Shizuku's friend at her school.
Original Cast: Maiko Kayama
Disney English Dub:Ashley Tisdale
Ms. Kōsaka (高坂先生, Kōsaka-sensei): The yōgo (health room teacher) at Shizuku's school whom she and her classmates sometimes hang out with.
Original Cast: Minami Takayama
Disney English Dub: Vicki Davis
Kinuyo and Nao (絹代, ナオ): Shizuku's other school friends.
Original Cast: Mayumi Iizuka, Mai Chiba
Disney English Dub:Mika Boorem, Abigail Mavity
Sugimura (杉村): Yūko's crush and Shizuku's friend.
Original Cast: Yoshimi Nakajima
Disney English Dub: Martin Spanjers
Shiho Tsukishima (月島 汐, Tsukishima Shiho): Shizuku's older sister and a college student.
Original Cast: Yorie Yamashita
Disney English Dub: Courtney Thorne-Smith
Kita and Minami (北, 南): Nishi's musician friends.
Original Cast: Toshio Suzuki, Naohisa Inoue
Disney English Dub: (Kita) Walker Edmiston, (Minami) Corey Burton