When the game was initially released in Japan, it was only available to people who bought a copy of the November 1996 cover-date issue of Japanese magazine CoroCoro Comic and filled out a mail-order form for the game. This promotion lasted from the day the issue was released on October 15 until December 27, 1996. As a result, on some official Japanese Nintendo and Pokémon websites, October 15, 1996 is listed as Pokémon Blue Version's first release date in Japan before it received a wider retail release there on October 10, 1999.

A recurring oddity in the Pokémon games is that the Gym Leader and later Elite Four member Koga, the Kanto Region's Poison-type expert, threatens to defeat his opponents with both Poison and Sleep tactics. In Red and Blue, he states:


In Gold, Silver, Crystal, and their remakes HeartGold and SoulSilver, he states:


In FireRed and LeafGreen, he states:


Despite this, the only game in the series where Koga's main team uses any Sleep-inducing moves is Yellow, where two of his Venonats have Sleep Powder. In contrast, all of Koga's teams have incorporated Poisoning moves, with some of his teams being entirely composed of Pokémon using such moves. Although possibly a mistake, this might also tie into the theme of misdirection, which would be fitting for the ninja-themed Fuchsia Gym.