I would like to know about the medical expenses system for children.

Children who have not yet entered elementary school are eligible for the Infant Medical Expenses Subsidy System (Marunyu). There is no income limit. Children in elementary school and junior high school can receive a medical expense subsidy system for compulsory school children (Maruko). There is an income limit here. In both cases, the self-pay portion when undergoing a medical examination at a medical institution under the application of health insurance is subsidized, and Maru Milk subsidizes 20% of the self-pay portion. Maruko will pay 200 yen for each hospital visit, and subsidize the remaining 30% of the copayment.
Note: For children in single-parent households, etc., the subsidy system for medical expenses for single-parent households (maru parent) may be prioritized.