About
About this site
Chuju Heigan is an independent decision-support service that designs junior-high entrance-exam application portfolios using public data and simulation.
What this service does
From your child's hensachi (deviation score), target schools, and available exam dates, we automatically build and compare 3–5 application portfolios balanced across expected admissions, risk, cost, and exam-date schedule.
Data and methodology
Built on 16 years of 80%/50% hensachi (deviation score), competition ratios, and exam outcomes published by 首都圏模試 (ONETES), 日能研, 四谷大塚, and SAPIX. We estimate an admission probability for each school and round, then run 10,000 Monte Carlo simulations per portfolio to evaluate the probability of at least one admission, cost, and how demanding the schedule is.
Independence
Run independently of cram schools and exam-prep media, with no incentive to favor any particular school or cram school. We work only from public data and present results explicitly as probabilities and expected values.
Current status
Currently in open beta. Free registration gives you unlimited simulations. We're preparing a full release ahead of the September 2026–February 2027 exam cycle.
How we handle your data
The hensachi (deviation score) and target schools you enter are used only to compute and, if you're logged in, save your portfolios. Our analytics are cookie-free.
Contact
Questions, requests, or corrections to our data — please reach out any time at the email address below.
contact@heigan.jpThis service provides decision support and does not guarantee admission. Final application decisions are your family's to make.