Until what age do Japanese kids believe in Santa?

At the parents on Japanlife, until what age did your kids believe in Santa? I'm working at a JHS and writing some stuff about the historical inspirations for Santa. And I don't wanna be the person to break to them that he isn't real.

So on average, at what age do Japanese kids stop believing in him? I assume it's around the same age as in Europe and America (10 years old), but I was just curious to see what your experiences are.

by BakutoNoWess