Does Japanese street racing consist mostly of modified cars or motorcycles?

i'm working on a project for my japanese class and i discovered Japanese street racing. However, most of the street racing is about cars, but my project is about motorcycles. So do street racers in Japan use modified cars more than they do motorcycles like Suzuki/Yamaha?





Thank-you!|||It's just as it is here in the US. There's a market for both, but the market for street racing with cars is more popular and less dangerous. The only thing different is they're more into drifting than drag racing.