To make things more difficult the stamps are only available between 9:30AM and 4PM so depending on the distance between selected station you may need several days. Part of the technique is to plan as many stops in a short distance as you can; so you travel around in these times and line up to stamp your book.
The kids at Osaki when I met Campbell were a short queue but I gather there can be up to hundreds lined up, and I am sure the kids, being Japanese, are very meticulous about stamping, getting the right amount of ink, and pressing firmly, then putting their book back in it's cover!
Parents are saints! So this time of year, the trains are swarming with kids in Pikachu visors, riding from station to station for no purpose other than to collect stamps for their booklet, which they`ll then send away for some token toy. They are escorted (often at a slower pace) by their saintly parent (usually mother and maybe Oba-san) who look as if they may collapse from heat exhaustion at any moment. I saw a few mothers stay on the seat and send the kid over to get their stamp where the JR station staff was enthusiastically calling them to come.
Unlike this guy I have never been into Pokemon, or even really know about it, but check out this blog of someone who decided to do it!! Obviously has some Japanese language skill and a good writer!!
http://goliweb.com/blog/labels/pokemon.htmlA summary of his efforts
-Japan is too hot in the summer.
-Air conditioning on trains is good.
-Too many Japanese people like pokemon.
-Japanese children can't walk in straight lines but they can run into things very well.
-Japanese people are too perfectionist and take way too long to do a simple stamp.
-I probably shouldn't still like Pokemon. The target audience is clearly 10 years old.
-The Yamanote line is pretty marvelous.
-Japanese adult pokemon fans are dangerous.
-Kumagaya is a long way away.
-Urawa station is a mess.
-Teleporting would be a very useful skill.