After making a serious mistake in his work in Tokyo, talented surgeon Goto Kensuke is invited to take charge of the only clinic on the small island of Yonaguni, Okinawa. It is difficult to get competent doctors to serve on this remote island, and the islanders are now used to traveling for hours via boat for proper medical care. Despite seeming weak and unreliable (he gets very seasick, and does not have a driving license), he wins over the skeptical islanders with his skill and dedication. Some children of the island make a flag for his clinic, but get his name wrong. Thereafter he is known by all as Koto.

Cast
* Yoshioka Hidetaka as "Dr. Koto" / Goto Kensuke
* Shibasaki Kou as Hoshino Ayaka
* Kobayashi Kaoru as Hoshino Seiichi
* Tokito Saburo as Hara Taketoshi
* Otsuka Nene as Nishiyama Mariko
* Izumiya Shigeru as Ando Shigeo
* Sengoku Noriko as Uchi Tsuruko
* Kakei Toshio as Wada Kasunori
* Ishida Yuriko as Harasawa Saki
* Oomori Nao as Sakano Takashi
* Tomioka Ryo as Hara Takehiro
* Asaka Mayumi as Hoshino Akiyo
* Sakamoto Nagatoshi as Nakamura Saburo
* Naya Shindai as Yamashita Kazuo
* Morikami Chie as Yamashita Michiko
* Haruyama Mikisuke as Yamashita Kunio
* Imafuku Masao as Yamashita Akio
* Ikeda Koushin as Miyano Junpei
* Tanimoto Mami as Miyano Mayumi
* Ohgo Suzuka as Nakamura Shuko
* Ohata Wakana as Kawahata Natsumi
* Funaki Masakatsu as Yamashita Tsutomu
* Takahashi Fumiko as Yamashita Harue
* Saito Daiki as Yamashita Shinichi
* Matsumoto Rina as Yamashita Momoko
* Shioya Shun as Hashiguchi Shun
* Kuriwaki Takashi as Fisherman 1
* Higashi Seichiro as Fisherman 2
* Kumagami Hiroyuki as Fisherman 3
* Yamanishi Atsushi as Motoki Wataru
* Matsuda Shiro as Yamashita Ju
* Yatsu Isao as Iwao Ji

Guests
* Minoura Yasuko as Kasai Mitsue (ep1)
* Kunimura Jun as Uchi Makoto (ep2)
* Sakurai Sachiko as Sakano Yukari (ep2-3)
* Takahashi Seiro as Sakano Tatsuro (ep3)
* Tabata Yuri as Sakano Kazue (ep3)
* Nakane Toru as Komura (ep3)
* Kimura Yoshino as Ashida Yuki (ep4,5)
* Ryu Raita as Ashida Ryuichiro (ep4,5)
* Izawa Ken as Abe Junichi (ep4,5)
* Shirakawa Kazuko as Abe Hiroko (ep4,5)
* Uzaki Kei as Kashiwagi Shuichi (ep5)
* Kamiki Ryunosuke as Sugimoto Ryuichi (ep5-7)
* Ito Ayumi as Ando Rika (ep7)
* Kashiwabara Shuji as Furukawa Toru (ep7)
* Tsuda Kanji as Kenji (ep9,10)
* Asami Reina as Yoshiko (ep9,10)
* Yamazaki Shigenori as Mikami Shinichi (ep10,11)