In Japan, where Boys’ Day originated, the holiday was joined with Girls’ Day to form Children’s Day. However, Hawaii set aside separate days for both sexes. Hence, Girls’ Day is observed on March 3, while Boys’ Day falls on May 5. A common sight in Hawaii’s neighborhoods during Boys’ Day is koinobori, large carp streamers or windsocks that “swim” in the tradewinds on bamboo poles in front of homes. Following tradition, each streamer represents a male in the household. The...