I didn't know TPMS is mandatory in US and EU about a decade ago. It's still not mandatory in Japan so most cars except luxury or imported don't equip it. Maybe

I didn't know TPMS is mandatory in US and EU about a decade ago. It's still not mandatory in Japan so most cars except luxury or imported don't equip it. Maybe vehicle inspection program (shaken) for every two years helps to avoid using worn tires. Also maybe due to less people use run flat tires than US/EU, or roads in Japan is better.