Asian phones tend to be problematic, as their cellular networks operate on different frequency bands than North American providers. The phone needs to support both 850 and 1900 MHz for (3G/HSPA/WCDMA), and 1700/2100 to work with (4G/LTE). Currently, koodo only uses LTE for data, so you could still use a phone as long as it supports the 3G frequencies. If it only supports the LTE frequencies though, you're out of luck.
depending on just how recently the phone in question has been released, you can generally check its compatibility at willmyphonework.net .