Takkyūbin — Japan's same-or-next-day courier delivery network, most visibly operated by Yamato Transport's black-cat-logo service — is used constantly by residents for ordinary parcel delivery, but it's also a genuinely underused tool for travellers moving between cities or hotels.
What it actually solves
Rather than hauling full suitcases through train stations, up and down stairs, and onto crowded services during a travel day, you can send your luggage ahead to your next hotel (or back to the airport ahead of your flight) and travel with just a day bag. For anyone doing Kyoto as part of a wider Japan itinerary involving multiple cities, this removes one of the most physically tiring parts of train travel.
How it works
Most hotels can arrange a takkyūbin pickup directly from the front desk, and convenience stores and dedicated counters at airports and major stations also handle drop-off. You pay per bag, address it to your next accommodation (which needs to know to expect it), and the bag typically arrives the next day for most domestic routes — same-day delivery is available on some routes but isn't the default, so it's not a same-morning solution.
Planning around the timing
Because next-day delivery is standard, plan to send luggage ahead the evening before you need it at the destination, not the morning of — for example, sending bags from a Kyoto hotel to a Tokyo hotel the night before a same-day Kyoto-to-Tokyo train, so the bags are already waiting when you check in.