My husband always took lunch in a lock & lock until I got him a Mr. Bento. The Mr. Bento itself is pretty boring, and the guys at work mostly think it's cool that we cook rather than get take-out like they do every night, and therefore he has something to bring for lunch allowing him to avoid the cafeteria (which ha poisoned people!).
Since lunch is usually leftover dinner from the night before, I don't bother with too much cutesy stuff, although when I've done it, he always likes it. (I doubt he shows it around though.) We do eat a lot of rice however, and he's been asked by co-workers who have never seen me if I am Asian. He always gets a good laugh out of that one! (I'm short, but a Jewish Easter-European Mutt, thank you very much!)
Since the black bag that came with the Mr. Bento wasn't too cool, my brother, the custom leatherworker, made us Mr. Bento carriers/covers
for our anniversary last year. Since my husband is into NASCAR and a Tony Stewart Fan, he got the 14 on his in the team colors. Mine has a tree, which is the logo for my chainmail business. They have handles that can be switched out for longer shoulder straps to give us more ways to carry them. Now the guys at work just think he's a rabid NASCAR fan, and they ignore the fact that it's a "cute little Japanese lunch".