Bamboo Blade" and one of the characters had a bicycle with a sidecar and I thought "Hmm... sidecar eh..." so I tried looking for that online.
Not many people have made a proper sidecar for a bicycle. Oh sure, there are children's sidecars and there are some custom made jobs like the one on the right here...
There is the Smike company in Switzerland which does mass produce, but to my knowledge they don't ship to North America. There are probably also some companies in China / Vietnam which also make sidecars for the local market. (Below you can see an example of a Smike bike with built in detachable sidecar.)
But nobody in North America mass produces them for adults. Its all children's sidecars / custom jobs. Even found one made for carrying pets.
I even asked a friend if he knew of any companies in North America that made bicycle sidecars. The closest thing he could find that was somewhat mass produced was Xtracycle's SideCar... and it is really more for carrying large boxes / groceries, etc.
Still, its worth noting. Check out the video below.
And further below here are some more photos of bicycle sidecars, custom or for kids, plus one motorcycle sidecar at the bottom which I have included just because it was so amazingly decorative.