April 4 is a day to express gratitude to brothers and sisters in the United States. Japan was registered with the Japan Anniversary Association as "Siblings Day" in 10.
People who have siblings who are sick or disabled are called "siblings" A new support group was established on April 4, which is designated as 'Sibling Day' and 'Siblings Welfare Association' The association aims to play a role in providing information such as experiences to people affected nationwide through its website, as well as connecting people affected with support groups.