The geographical distribution of today's family names, moving roughly north to south from Hokkaido to Okinawa and listing the five most commonly found in each prefecture in order of occurrence.

Hokkaido: Sato, Takahashi, Sasaki, Suzuki, Ito

Aomori: Kudo, Sato, Sasaki, Kimura, Narita

Iwate: Sato, Sasaki, Takahashi, Chiba, Kikuchi

Miyagi: Sato, Takahashi, Suzuki, Sasaki, Abe

Akita: Sato, Takahashi, Sasaki, Ito, Suzuki

Yamagata: Sato, Takahashi, Suzuki, Saito, Ito

Fukushima: Sato, Suzuki, Watanabe, Saito, Endo

Ibaraki: Suzuki, Sato, Kobayashi, Watanabe, Takahashi

Tochigi: Suzuki, Watanabe, Saito, Sato, Kobayashi

Gunma: Takahashi, Kobayashi, Sato, Arai, Saito

Saitama: Suzuki, Takahashi, Sato, Kobayashi, Saito

Chiba: Suzuki, Takahashi, Sato, Watanabe, Ito

Tokyo: Suzuki, Sato, Takahashi, Tanaka, Kobayashi

Kanagawa: Suzuki, Sato, Takahashi, Watanabe, Kobayashi

Niigata: Sato, Watanabe, Kobayashi, Takahashi, Suzuki

Toyama: Yamamoto, Hayashi, Yoshida, Nakamura, Yamada

Ishikawa: Yamamoto, Nakamura, Tanaka, Yoshida, Yamada

Fukui: Tanaka, Yamamoto, Yoshida, Yamada, Kobayashi

Yamanashi: Watanabe, Kobayashi, Mochizuki, Shimizu, Fukuzawa

Nagano: Kobayashi, Tanaka, Nakamura, Maruyama, Ito

Gifu: Kato, Ito, Yamada, Hayashi, Watanabe

Shizuoka: Suzuki, Watanabe, Yamamoto, Mochizuki, Sugiyama

Aichi: Suzuki, Kato, Ito, Yamada, Kondo

Mie: Ito, Yamada, Nakamura, Tanaka, Suzuki

Shiga: Tanaka, Yamamoto, Nakamura, Nishimura, Yamada

Kyoto: Tanaka, Yamamoto, Nakamura, Inoue, Yoshida

Osaka: Tanaka, Yamamoto, Nakamura, Yoshida, Matsumoto

Hyogo: Tanaka, Yamamoto, Inoue, Matsumoto, Fujiwara

Nara: Yamamoto, Tanaka, Yoshida, Nakamura, Matsumoto

Wakayama: Yamamoto, Tanaka, Nakamura, Matsumoto, Maeda

Tottori: Tanaka, Yamamoto, Yamane, Matsumoto, Maeda

Shimane: Tanaka, Yamamoto, Sasaki, Fujiwara, Takahashi

Okayama: Yamamoto, Miyake, Fujiwara, Sato, Tanaa

Hiroshima: Yamamoto, Tanaka, Fujii, Sato, Takahashi

Yamaguchi: Yamamoto, Tanaka, Nakamura, Fujii, Harada

Tokushima: Sato, Yoshida, Kondo, Mori, Tanaka

Kagawa: Onishi, Tanaka, Yamashita, Takahashi, Yamamoto

Ehime: Takahashi, Murakami, Yamamoto, Ochi, Watanabe

Kochi: Yamamoto, Yamazaki, Komatsu, Hamada, Takahashi

Fukuoka: Tanaka, Nakamura, Inoue, Koga, Yamamoto

Saga: Yamaguchi, Tanaka, Koga, Matsuo, Nakajima

Nagasaki: Yamaguchi, Tanaka, Nakamura, Matsuo, Matsumoto

Kumamoto: Tanaka, Nakamura, Matsumoto, Murakami, Sakamoto

Oita: Sato, Goto, Watanabe, Ono, Kawano

Miyazaki: Kuroki, Kai, Kawano, Hidaka, Sato

Kagoshima: Nakamura, Yamashita, Tanaka, Maeda, Higashi

Okinawa: Higa, Kinjo, Oshiro, Miyagi, Aragaki

Source for both lists: "Myoji no Himitsu" ("Secrets of Family Names"), by Hiroshi Morioka (Asahi Shimbun Shuppan, 2009)