There are many things and services that make life a lot easier in Japan, many of which we sorely miss when traveling in other countries. One of the best ones is definitely takkyubin, which is basically a courier delivery service. While you can FedEx things like documents in most countries, this service in Japan does a lot more and is much more affordable. Several companies offer similar services, but the most popular company is Kuroneko Yamato. Their logo with the black cat and their delivery trucks can be seen all over Japan.
We often have our online orders delivered by Kuroneko and they offer special services like safe delivery of laptops. If you are traveling in Japan, the one thing you should definitely consider is the suitcase delivery. This really makes sense because you can have your suitcases and bags delivered to or from the airport, making traveling so much easier. Whenever we send our suitcases it costs 1690 Yen (just over $17 as of today) to have a 50lb suitcase delivered anywhere on Honshu. Here is a list of the service counters at different airports and these are the convenience stores that offer the service. For delivery to the airport, you need to send it at least two days before your flight.
If it is not too late in the day, you can have your luggage arrive the next day and they even let you choose what time of day you would like it to arrive. In our experience, they are always on time and we have never had any issues. If you are not home, the delivery person leaves a note with their cell phone number on it so you can call and ask for redelivery at whatever time is convenient.
One thing to remember is that when you send your luggage ahead to the airport, they need to know things like your departure time and flight number. Just make sure you have your reservation info on hand when going to fill out the form. We have a members card that has our address stored so we do not have to fill out the form every time. The staff are usually really friendly and they make sure everything is correct and even fill out the form for you. We sure wish we had known about this service when we first came to Japan. There is no need to lug heavy suitcases around, give it a try!