Background: This is a preliminary study of Japanese co-workers’ attitudes towards migrant workers’ Japanese language skills in blue-collar workplaces. This is an important topic, seeing as Japanese co-workers’ attitudes can result in inequalities at the workplace, directly impacting migrant workers’ everyday lives. Understanding these attitudes and addressing them can improve migrant workers’ experiences. Methods: The study is based on content analysis of documents taken from English-language sources. Results: The author found that Japanese co-workers and employers assume ownership of the means of communication, expecting only Japanese to be used at the workplace. They also underrate migrant workers’ Japanese proficiency. Conclusions: Although the data has its limitations, the study provides some insight and can potentially serve as a base for further research.