Surname Kotsugai (Kotsugai 
) , around the globe, is quite a common last name. The last name Kotsugai is characteristic of Japan, where it is quite a rare surname, Brazil, where it is an extremely rare surname, and China.
| VARIANT | COUNTRY |
|---|---|
| Kotsugai | Japan, China, Philippines, United States, Brazil |
Ko, Toshio, Tereza, Hazuki, Yoshio, Yoichi, Marisol, Shokichi, Takuya, Antonio, Takashi, Hiroshi, Hitoshi, Shinichi, Andressa, Frediano, Isabella, Akihiro, Daniel, Kiichi, Koichi, Shin, Alan, Koji, Maria, Masao, Aline, Agnes, Akira, Akemi, Kazuo, Kenji, Ryoji, Tadao, Yukio, Monica, Susumu, Kazumi, Frederico, and Alessandra