Let the school know you're thinking of applying — they can share their prerequisites and help you through the process.
It's best to ask — circumstances can change at any time.
English is the language of classroom instruction. Japanese language instruction occurs daily in ability-based classes. ESL services and learning support are available to non-native English speakers. The curriculum overview notes that the program emphasizes learning multiple languages and foreign language study, but does not specify which languages beyond Japanese are offered or whether language study is mandatory.
United School of Tokyo (UST) is an international school in Shibuya, founded in 2014 by parents and teachers, serving children ages 3 to 14 across Kindergarten (K1–K3), Elementary (G1–G5) and Middle School (G6–G8). Classroom instruction is conducted in English and the school references American Common Core standards for benchmarks. UST highlights small classes and notes 16 students per class and a total of ~220 students. Japanese is taught daily, with additional language options mentioned for older students. Beyond lessons, UST runs an extracurricular program with 30+ classes across sports, performing arts, visual arts, games/activities and STEAM. A distinctive feature described under school life is its Social Responsibility work, including projects like eco drives and a partnership-building effort with an elementary school in Cambodia.