Jinseki International School (JINIS) opened in April 2020 on the Jinseki plateau in eastern Hiroshima Prefecture, and describes itself as Japan's first full-boarding elementary school. It takes children from Grade 1 to Grade 6 (ages six to twelve), and every pupil boards from the first year. The school is run by the Jinseki Kogen Gakuen educational corporation, founded and chaired by Minako Suematsu.

JINIS is an "Article 1" school under Japan's School Education Act, so it is a fully recognised Japanese elementary school, and it holds special-curriculum status from the Ministry of Education (MEXT) as an English-immersion programme. Its own curriculum combines the Japanese national curriculum with the International Primary Curriculum (IPC), the thematic, inquiry-based primary programme developed in the UK in 2000; the IPC accreditation mark (2023–25) appears on the school's website. Each year group has two teachers, one international and one Japanese, and most lessons are taught in English, so children keep pace with Japanese standards while learning to think and work in a second language. No English is required for Grade 1 entry; families who do not speak English are not at a disadvantage, as everything the school sends home is written in both Japanese and English.

The rural setting is used deliberately. Under its Nature Programme, pupils grow vegetables on the school farm, collect honey and help care for cattle; with local farmers they plant and harvest rice, then pound it into mochi or sell it as "JINIS rice" — a first, practical lesson in how society and the economy work. Children observe life in nearby rivers, follow lunar eclipses and the phases of the moon, and carry out IPC science experiments with real soil and plants. The school also teaches safety and disaster preparedness, along with food education and consumer education built around boarding life.

Japan is treated as the host country. Pupils take part in tea ceremony and zazen meditation, mochi-making, Hinamatsuri and Koinobori, while international staff lead bonfire night, Christmas and Chinese New Year. Physical education runs on a seasonal rotation: cycling and swimming in the first term, golf and tennis in the second, and skiing and skating in the third. The year is divided into three terms, with a Spring Trip, Sports Day, Autumn Trip, a JINIS Concert and a Ski Trip.

Boarding is the whole school rather than an option within it. House parents live in the boarding house, staff look after the children around the clock, and on-site security staff monitor visitors; the school sits away from residential areas in a quiet town. Facilities listed by the school include classrooms, a library, a dining hall and play garden, and in the boarding house a Japanese garden, playroom, pool, bath and kitchen. The menu is advised by chef Keisuke Matsushima, with an emphasis on umami and local produce, and the uniform was designed by Tae Ashida. Weekends fall on Friday and Saturday, with regular lessons on Sunday. Advisors include Rob Gray, former head of Institut Le Rosey, and John Baugh, former head of the Dragon School, Oxford.

Capacity is 24 pupils per year group (144 in all), and the school says classes are small. The school's stated aim is to prepare children for senior boarding schools overseas, and it publishes a list of destination schools including Institut Le Rosey, Dragon School Oxford, Millfield, Geelong Grammar School, The Fessenden School and Shawnigan Lake School. Because it is an Article 1 school, its leavers can equally go on to Japanese public or private junior high schools.

Admissions are handled individually rather than through a single entrance examination, and run throughout the year. For April 2027 the school is recruiting twelve Grade 1 pupils; transfer places are offered when a year group has room. Families start with a one-to-one online information session, visit the campus, and can book a two-night trial stay. The school recommends that children who plan to join Grade 1 attend its summer camp in their final kindergarten year (K3).