I'm Japanese and grew up in a Canadian prairie city. (IOW I was the only Asian kid in my class sometimes.) My mom would get me the cutest, coolest obento boxes from Japan with the latest anime fad on the lid. I really liked them, but when I was in 5th grade and at a new school, some kid in my elementary school commented that my bento was "weird", and I demanded that my mom make me normal lunches - sandwiches and carrot sticks in ziploc bags, no frills!
When I was in high school, I was very busy and my mom still lovingly made my lunches. I allowed the bento box (without anime characters) to return to my backpack, but still asked my mom to keep it simple. Nothing too ethnic-looking, like onigiri or inari sushi. I still really wanted to blend in, and my mom was understanding of how I felt.
My daughter is only 1 year old, and will be going to a Japanese preschool when she's 3, but I love that there is a growing Western bento community. We also live in a more multicultural area, where I'm not the only one speaking a non-English language to my kid. Maybe by the time she is going to school, 'lunches in a box' will be more accepted? I can only hope.
I applaud all of you and your children who take your bentos out into the world with pride.