From his debut in NPB, NTV & Toho (and later Upper Deck for his MLB home runs with the Yankees) issued a card for every one of Hideki Matsui's home runs....as he hit them. So all of the photos are from the actual home run or game, not like Topps and Upper Deck (in the US) where they issue a set of 500 cards and employ like 5 different photos.
The cards are all about the size and shape of a phone card, with rounded corners, and I'm guessing a description of the situation of each home run. They're pretty much broken up into a set for each season he played, as the year is listed on the front, and the actual date of the home run on the back. Here's a not so random sampling:
Lots of bats flying through the air, lots of home plate congratulations, but I think my favorites are those where you can see the ball leaving Matsui's bat.
And somehting you might notice about the Giants' helmets that separate them from every other team I've ever seen is that they aren't glossy and shiny. They have a very cool matte-style finish that seems to make them almost glow on the card as if they were added later as a digital effect. You'll see it a lot more in some of the Tuffy Rhodes cards when I get to them. I think the Yankees should adopt that style of finish on their helmets for a year. it would have been awesome had they done it when Godzilla joined the team.
In 1997, the cards got an upgrade and they added color to the backs:
If you notice just above the photo, this was home run #2 of the 1997 season.
Starting with #100, every multiple of 50 was a special card. I don't have 100 or 150, but I do have 200 & 300:
Blogger/teacher/Marinerd Deanna Rubin paid a visit to the Hideki Matsui museum in Japan about 2 years ago, and the museum (run by the Matsui family) actually has what look like 8x10 versions of many of this set on display as a part of the museum. Have a look:
Deanna at the Hideki Matsui Museum
And while you're there, browse around Deanna's great site. She takes the absolute BEST photos during the hundreds of baseball games she attends each year.