Kanso is internationalization-compliant and makes use of the respective tags throughout the template, which means that you can change the hard-coded theme strings by using any of the third-party plugins such as Quick Localization. When translating the strings, please use “satori” as theme’s language domain.
Should you have additional questions, do not hesitate to contact me!
please make sure that:
1). the field for the string to translate is case-sensitive, so you must have “Send Message” and not “send message” there
2). the “domain” (or “text domain” depending on the plugin version) field should say “satori”.