Surname Koshun (Koshun 
) , in the entire world, is a rare last name. The surname Koshun is habitual in Japan, where it is a rare surname, and Ukraine, where it is an extremely rare surname. Much more prevalently, Koshun is the forename as well as the last name.
Abe, Kuroda, Kimura, Tanaka, Nakano, Yamada, Matsuda, Machida, Shimizu, Shibata, Shigeki, Togashi, Okumura, Yamaoka, Yoshida, Maruyama, Sakamoto, Nakamura, Watanabe, Yamamoto, Kobayashi, Takahashi, Kojima, Kaneko, Suzuki, Sugama, Lee, Ito, Ono, Sato, Baba, Kato, Rice, Devi, Uema, Maeda, Yamashita, Sakai, Koide, Nagai, Nakao, Ikeda, Osada, Ogura, Ogawa, Matsuo, Mizuno, Sasaki, Kondo, and Matsushima