What year does this story take place in if they have Nintendo Switches in kindergarten?
I was thinking the same thing.
The first Switch released March 2017, six years ago. If they are ages 3 and 5 (or thereabouts), then 15 years later tracks with the university age (18+ and 21+ or so), meaning in current times (as of posting this comment) they'd be in elementary to middle school (9 and 11), then their high school times would be about 6 years from now when they are round the ages of 14 and 17.