All public elementary, junior high and high schools in Japan raised the Hinomaru during their spring graduation ceremonies, according to an education ministry survey released this week.
This marks the first time the flag has been hoisted at all the schools in question since 1999, according to the Education, Culture, Sports, Science and Technology Ministry.
In 1999, the Hinomaru was legally recognized as Japan's national flag, while "Kimigayo" ("His Majesty's Reign") was recognized as its anthem.
In line with this, authorities have been instructing public schools to hoist the flag and sing the anthem during formal events such as entrance and graduation ceremonies.
Yet the issue of official recognition remains a sensitive one due to their symbolic links to Japan's Imperial system and its past militarism.
Similar results were also seen during April entrance ceremonies. The Hinomaru was flown at 100 percent of both elementary and high schools, and at 99.9 percent of junior high schools.
As for "Kimigayo," 99.8 percent of elementary and junior high schools had it sung during graduation ceremonies, while the rate stood at 99.9 percent for high schools, the survey showed.
The enforced singing of "Kimigayo" at elementary and high schools during entrance ceremonies also neared 100 percent.
The Japanese school year starts in April and ends in March.
Schools in 39 prefectures and 12 government-designated major cities enforced both the raising of the Hinomaru and the singing of "Kimigayo."
Kanagawa Prefecture and the city of Kawasaki, as well as the cities of Osaka and Kobe, were additions to the list.
The enforced singing of "Kimigayo" was lowest among junior high schools in Nara Prefecture, during entrance ceremonies, at 93.5 percent, according to the survey.
Last year, elementary schools in Hyogo Prefecture recorded the lowest enforcement of "Kimigayo" in entrance ceremonies, at 83 percent. This year's figure rose to 98.9 percent.