Scott Inoue, who is shown with zero in a photograph his mother captioned as being from grade three, never mentioned it. And as zero's records have been 'LOST' there's no confirming or denying it, so the questions remain.
The absence of mention is not the same as confirmation or denial. It is possible to track down other people who are in the photo and ask them. The two student-teachers are in the photo and they have confirmed.
Scott doesn’t remember him in kindergarten, only third grade.