Each summer, Japan Post Insurance distributes rajio taisō shusseki kādo, attendance cards for radio calisthenics, mainly through elementary schools. In 2025, distribution began on June 9. The cards encourage children to get up early during the summer vacation.
In an essay published by the Postal Museum, the writer recalls the morning routine. After the exercises, the pupil from the top grade who led the group stamped the card each child had brought, as sanka no akashi, proof of taking part.