ABSTRACT Research into Japanese language education and the intersections of gender and sexuality has demonstrated the importance of critiquing heteronormative biases in teaching materials and resources. We propose that collaborative approaches which decentre regimental heteronormative understandings of the Japanese language and which facilitate inclusivity and affirmation of sexual orientation, gender identity, gender expression, and sex characteristics (SOGIESC) are crucial to sustainable practices in Japanese language education at all levels. Adopting a critical reflexive stance, we first trace the community advocacy which has resulted in changes to representations of sexual identities in Japanese dictionaries. We next critically examine Japanese language education materials which are used across a diversity of locales before offering some practical ways in which small changes can be made to ensure greater inclusion and affirmation of SOGIESC in local learning environments. Further, we discuss the importance of developing metalinguistic awareness in relation to gendered speech styles and language ideologies. We argue that collaboration and co-construction are fundamental to sustainable practices which learn from histories of advocacy and research, are responsive to shifts in Japanese society and culture, and adaptable to a diversity of learning environments.