Yu-Gi-Oh! (遊☆戯☆王 Yūgiō , lit. "Game King" or "King of Games") is a popular Japanese manga created by Kazuki Takahashi and originally serialized on the Weekly Shōnen Jump magazine. The original story focuses on Yugi Muto and his alter ego, Yami Yugi, with most of the conflicts being solved in the form of various gambling games. The series would spawn various anime and video game adaptations, all of which focus exclusively on the Duel Monsters game (originally called Magic & Wizards in the manga), a trading card game in which each player assembles a deck of cards depicting fantasy monsters, consisting on three types of cards: Monster, Spell and Trap, with which they challenge other –similarly equipped– opponents with the objective of defeating them and obtain the victory, as well as some of their own cards.
The series began as a manga in Japan in 1996, and since then it has grown to an immensely successful global brand, spawning various manga and anime series, video games, toys, and many other products. Most importantly, a real trading card game named Yu-Gi-Oh! Trading Card Game, based on the Duel Monsters game from the story, was later developed and published by Konami, featuring cards based on the monsters from the manga and anime series. Konami also created their own cards, some of which are based on various Konami properties, which later made their way into the anime and video game adaptations. Many of these cards are based on Konami's various shoot 'em up titles, with an entire set dedicated to the Gradius series. GetsuFumaDen, Castlevania, and Ganbare Goemon are no exception, and cards based on these and other franchises have also appeared in certain releases.
References to the GetsuFumaDen series
- The card Getsu Fuhma depicts the original Getsu Fuma with his iconic Hadou katana. It has an ability that gives the player an advantage over Fiend and Zombie-type monsters.
- The card Ryu Kokki depicts Ryukotsuki, called "Ryu Kokki" in English due to a translation error, in an updated version of their bone dragon form. Like Getsu Fuhma above, Ryu Kokki grants an advantage against Sorcerer and Warrior-type monsters.
- The card Fuhma Wave depicts a confrontation between Getsu Fuma and Ryukotsuki.
- A card named Disciple of the Forbidden Spell, called "Fuhma's Disciple" in Japanese, depicts a young warrior with dual blades, spiked gauntlets, a war drum, and several paper ofuda talismans. Like Getsu Fuhma, the Disciple has an ability that gives it an advantage against a given monster type, but this time of the player's choosing. Additionally, an additional type may be selected for each copy of the Disciple already in its player's graveyard, suggesting some implications about how many disciples Fuma may have gone through while reestablishing the clan after the events of GetsuFumaDen.
- The titular "Forbidden Spell" is portrayed in another card, Flash of the Forbidden Spell ("Fuhma Flash" in Japanese), and likely refers to Raigeki, a powerful spell from early in the card game's lifespan that was banned in official play for being too powerful.
- Ryu Kokki also serves as one of the Limited Duel opponents in Yu-Gi-Oh! Ultimate Masters: World Championship Tournament 2006, challenging the player to defeat her using no monsters that are not Zombie-type.
- The Ryu Kokki card also appears in the 33rd episode of the Yu-Gi-Oh! GX anime, although Ryu Kokki herself is not summoned.
- The cards themselves also show up in many of the Yu-Gi-Oh! video games that have been produced.