The essentials (bring these no matter what)
Portable charger
Allowed at all Japanese stadiums. You'll burn through battery taking photos, checking stats, and using Google Translate on food stall menus. A 10,000mAh charger is enough for one game.
IC card (Suica/Pasmo)
Load ¥2,000-3,000 before the game. Works for stadium food stalls, convenience stores, and your train ride home. Available at any train station.
Cash
¥3,000-5,000 backup. Some smaller food vendors inside stadiums are still cash-only.
Towel
The universal Japanese fan accessory. Wave it during cheers, wipe sweat in summer, wrap around your neck when cold. Buy a team towel at the stadium shop (¥1,500-2,500) and you've got a souvenir too.
Weather-dependent items
Rain poncho (outdoor stadiums)
Umbrellas are banned during games. Buy a clear poncho at any convenience store for ¥100-300.
Warm layers (spring/autumn night games)
Outdoor stadiums get cold after sunset. Even if it's warm during the day, bring a jacket for night games in March-May and September-October.
Sunscreen + hat (summer day games)
3 hours of direct sun at an outdoor stadium will burn you. Dome stadiums don't need these.
Nice to have
Seat cushion (hard plastic seats for 3 hours). Binoculars (especially from outfield seats). Plastic bag (for trash and protecting belongings if it rains). Mini megaphone bat (¥500-800 at the stadium — join the cheering).
Don't bring
Cans or glass bottles (prohibited). Tripods or selfie sticks (banned). Full-size umbrella (can't use it). Outside alcohol (most stadiums prohibit it).
How to buy tickets
Official team sites or English-language platforms with international card support. Have your e-ticket screenshot saved on your phone in case of poor signal at the gate.