You often see the combination of red and white at celebrations in Japan.
It calls “Kohaku”.
Kohaku has deeply meaningful for Japanese people.
For example, the stage has a red and white striped curtain at a wedding ceremony, an entrance ceremony, a company ceremony.
They often hand out red and white buns with a bean-jam filling or rice cakes at these ceremony.
There are many theories about the prevalance of the combination.
The most popular one dates back to 12th century,
when the two leading clans, the Tairas, or Heike and the Minamotos, or Genji,fought a series of battles.
The conflict ended with the fall of the House of Taira and the establishment of the Kamakura government by the Minamotos.
The Taira clan flew red flags on the battlefield, while the Minamoto side used white ones, so red and white came to represent the opposing forces.
