Which card
Residents: Suica or PASMO. Short stays: Welcome Suica or a phone wallet. Not every machine takes overseas cards.
Is a JR Pass worth it
Tokyo city only: ordinary Suica beats a nationwide JR Pass. Price the Pass against shinkansen or Hakone / Nikko / Kamakura days. Yamanote, Chuo and Keihin-Tohoku are JR; metro and Toei need extra pay or a Tokyo Subway Ticket.
Last trains
Most lines wind down around midnight; suburbs earlier. Check Yurikamome, Inokashira and Narita Skyliner last runs — do not gamble.