<prompt> I-JR East isebenzisa inethiwekhi enkulu kunazo zonke yezitimela eTokyo, kufaka phakathi i-Yamanote Line loop ezungeza isikhungo sedolobha laseTokyo. Izinhlangano ezimbili ezihlukene zisebenza ngenethiwekhi kamasipala: i-Tokyo Metro yangasese kanye nohulumeni iTokyo Metropolitan Bureau of Transportation. Uhulumeni waseTokyo kanye nabezimboni ezizimele basebenzisa imizila yamabhasi kanye nomzila owodwa wetramu. Izinsizakalo zasendaweni, zesifunda nezikazwelonke ziyatholakala, ezinemigqa emikhulu eziteshini ezinkulu zezitimela, kufaka phakathi iTokyo, iShinagawa neShinjuku. Umbuzo: Uyini umugqa owodwa wesitimela eJapan?  <response>: I-Yamanote Line loop 