The common depiction of LGBTIQA+ identity in manga generally revolves around gendered fantasy, either from female gaze on forbidden love in yaoi genre or the gay gaze on masculinity in bara genre. As such, the publication of Gengoroh Tagame’s graphic novel, “My Brother’s Husband”, is considered a breath of fresh air in terms of authentic representation within the manga sphere. The book itself revolves around the journey of Yaichi, Mike, and Kana in exploring and accepting / tolerating new, sometimes alien concepts of sexuality and identity within the setting of intercultural encounters. Despite the dynamic interactions between these three characters, the child (Kana) plays an important role in sparking, facilitating, and sometimes leading the dialogues that further explore the complexity of sexuality and identity from both Canadian and Japanese perspectives. This paper aims to study how the child agency and activism is portrayed and used in this book to help both the child and adult readers to navigate the complex issues, such as interculturality, identity, and sexuality. The rise of Kana into an active citizen and how she claims her own space in the public sphere and debates of sexuality and identity become the focus of this study. The child mediation, agency and activism in the book are analysed using the framework of intergenerational solidarity and the idea of “child-as-kin”. Focus on the visuality and image seriality is also employed in the study, considering the importance of visual layers in the graphic novels in telling story, the potential to further engage the readers and build the affective foundation to finally embrace diversity.