Mameta Endo is a writer and trans activist based in Tokyo, and the founder and representative of Niji-zu, a safe space for LGBTQ youth. As a trans person, Mameta began his activism in his teenage years and has nearly 20 years of experience as an activist.

Mameta educates on LGBTQ issues through books, lectures, and training programs. He has published five books related to the LGBTQ community in Japan, including An LGBT Guidebook for Teachers and Parents: What to Do If a Child Comes Out to You (Godo Press, 2016). He also runs the educational website trans101.jp, which provides accessible information on transgender issues and gender diversity.

Mameta leads Niji-zu, which offers safe spaces for LGBT and questioning youth from their teens through age 23. Niji-zu is one of the most well-known LGBT youth services in Japan, providing opportunities for LGBTQ teens and young people to connect with peers. The organization currently operates 17 branches nationwide, including in Tokyo, Sendai, Kyoto, and Osaka, and also offers a safe space in the metaverse.