I knew Tokyo's transit system could be a beast, so I made sure to do my homework regarding local SIM card options before my flight. I settled on the Mobal SIM card https://www.mobal.com/japan-sim-card/ , and it turned out to be an absolute lifesaver. Dropping pins on Google Maps and translating train schedules in real-time was totally seamless. Having internet right from the tarmac let me jump straight into exploring without that usual first-day travel anxiety.