Although this is believed to be the first Pokemon Trading Card Game event held in Japan, it's not considered the 1st Official Tournament--that wouldn't be until the 6th World Hobby Fair a few months later. The 5th Next Generation World Hobby Fair was held at the Makuhari Messe convention center in Chiba from January 12th through 13th, 1997. The January 1997 issue of CoroCoro Comic (released December 15, 1996) includes a tiny blurb about the rules used at this event (down in the bottom left corner of this picture, near the grass energy symbol). Thanks to Seiro of Zoidsland for providing the magazine scans!
I don't know much about this event (yet!), but here's what I do know:
The event took place January 12-13, 1997, which means the only two rule books available were the 1st Edition rules (1996-10-20) and the 1st edition of Easily Understand How to Play Pokemon Cards (1996-11-30). The latter introduced a couple of "official rules" which were reiterated in the CoroCoro Comic page I linked above. Those rules are:
If you aren't familiar with Japan's oldest rule books, that second point may seem strange. As it turns out, the very first rulebooks included with Japan's 1st Edition Starter Packs did not allow players to bench any Basic Pokemon during setup. You got your Active Pokemon, and nothing else. This, of course, made it very easy for the player going first to OHKO their opponent's Active Pokemon on turn 1 and win the game immediately. Allowing players to bench a Pokemon during setup made this much less likely--especially if players were following the recommended deck construction ratios of 20 Basic Pokemon Cards, 5 Evolution Cards, 10 Trainer Cards, and 25 Energy Cards. Players wouldn't be free to bench multiple Pokemon during setup until some time later, strange as that may seem to us today.
There's actually another rule change--clarification? correction?--in Easily Understand How to Play Pokemon Cards that wasn't mentioned in that CoroCoro page, but I believe would have been in place for this event anyway. It pertains to the "Sleep" condition, and can be found on page 23 of the book. It explains that, although the original rule book states that a sleeping Pokemon will wake up automatically during the Pokemon Check phase following their opponent's next turn, that is not the case. Rather, the player whose Pokemon is asleep must flip a coin during each Pokemon Check phase (after each turn), and the Pokemon will only wake up if the coin lands on Heads. This is the same sleep rule we've been using for the last 27+ years, so you don't need to think too hard about it. They don't make it clear whether the original rule book's explanation of the Sleep rule was a mistake or not, but it seems to me that it probably was.
Other regulations specific to this event, such as time limits, prize counts, etc., are not known. If I find any more information, I'll update this page! Until then, we can probably assume they used standard 60-card decks with 6 prizes, but I have no idea about time limits.
The following cards were all that existed at the time, so logically they would have formed the legal card pool for the event:
Many readers may be aware that Wizards of the Coast didn't always translate everything correctly, so many WotC-era cards would need erratas to function as originally intended. I'll go over those elsewhere, and that link will take you there when I eventually do. For now, though, I want to talk about something else: cards that would receive errata in Japan. The following cards functioned differently at the time of this tournament than they did by the time those same cards were printed in English:
