In the first year of the Demon Age (14672), a horrible demon named Ryukotsuki was revived by his minions in hell. To protect the peace of the overworld, the two eldest Fuma brothers fought Ryukotsuki. Both were unable to defeat him and were killed, losing their legendary Pulse Blades. To avenge their deaths, the last of the Fuma brothers vowed to slay Ryukotsuki and retrieve the swords.
While never released outside of Japan, there are English Fan Translations. Getsu Fuma and Ryukotsuki, however, have occasionally appeared (or at least having influences) in other Konami media, such as in Yu-Gi-Oh!, Neo Contra, Hard Corps: Uprising, Otomedius (although they both are represented by girls in that game), and Castlevania: Harmony of Despair.
In an unexpected move from Konami, a Revival sequel titled GetsuFumaDen: Undying Moon was released worldwide. It first launched on Early Access via Steam on May 13, 2021, released for Nintendo Switch on February 9, 2022, and then left Steam Early Access on February 16, 2022.
This game provides examples of:
- Action Girl: Getsu Renge, added in a latter patch in Undying Moon. She's much more of a Glass Cannon than Fuma as well as being able to move faster on foot than him.
- After the End: The game is set in the distant future, but the Big Bad Ryukotsuki has almost wiped out humanity. Technologies are, at that time, very, very scarce, and at the very least, Japan has just re-advanced to technologies of the Warring States era.
- Anti-Frustration Feature: In Undying Moon, when you kill enemy mid air and their loots fall off into places that can cause environmental damage (falling off to the sea, bottomless pit, or bed of spikes), the loots will respawn in the nearest place that are safer (This is not something in the original game where if your enemy drops something like money bag or soul, they stay in place or float upwards)
- Attack Its Weak Point: 3D dungeon enemies in the original usually don't take any damage by just hitting them with your sword. But if you hit them on the top center part of their sprite (usually, the center of their head), they have a different 'damage animation', which signifies their weak point, after hitting that spot twice or thrice, they go down.
- Attack of the 50-Foot Whatever: Ryukotsuki's final form. And by Undying Moon, every bosses except one (Getsu Rando) are like 50 foot Japanese mythological monsters that tower above Fuma.
- Dark Is Not Evil: Fuma has several demonic motifs, utilizes the souls of the dead to empower him, and his Super Mode is called 'Demonization'. He's also a heroic figure who fought and hold off The Legions of Hell from invading the world on a daily basis.
- Fire and Brimstone Hell: Technically, in every game, Fuma traverses to Hell and in the original game, there were some 8-bit fiery hell scenery. In Undying Moon, traversing to Hellfire Cliffs gives you the scenery of a fiery Ancient Japanese Hell where various Oni in the background are tormenting the damned, all painted and animated in terrific ukiyo-e style art.
- Embedded Precursor: Digital Deluxe and physical copies of Undying Moon came bundled with a port of the original famicom game, handled by M2. Notable of being it's first official release outside japan, but the game is left untranslated.
- Identical Grandson: In Undying Moon, the playable Getsu Fuma is actually a same-named descendant who looked just exactly like the original Fuma that defeated Ryukotsuki and recovered the Wave Sword in the NES/Famicom game.
- Invincible Minor Minion: The talismans that move and attack Getsu Fuma when he gets close enough. Luckily, they don't deal much damage, are easy to dodge enough, and appear late enough in-game that you should have access to items/weapons to reduce the inflicted damage or No-Sell their attack, and the stages where they appear have no Bottomless Pits.
- Jump Physics: The game lets you jump in mid-air after falling off a ledge. This proves useful for collecting power-ups hovering over Bottomless Pits.
- Luckily, My Shield Will Protect Me: Ryukotsuki's second form sports a shield that it can use to block your attacks, though it's not big enough to cover it entirely. In Undying Moon, Fuma himself can use his Parasol of Pain as a makeover shield.
- Magikarp Power: Your sword starts out really weak and generally has an unsafe range on hitting the enemy as it's short and you better hope you can take advantage of the enemy's Mercy Invincibility to avoid damage. But, using the sword constantly makes it stronger (and culminates in the strength of your Pulse Blade when you get it, which completely busts out the game), whereas other weapons, while having a more safe usage, don't have such progression system and stays stuck in the same power level.
- Meaningful Name: Also a Bilingual Bonus when you consider that the word "Getsu" (月) can be translated as "moon", the name of the reboot Undying Moon is a reference that the members of the Getsu clan revive upon death in this rogue-like adventure.
- Multi-Melee Master: In Undying Moon, Fuma is an expert of multiple melee weapons instead of limiting his melee to just mere katana. Katana is still there, but he can also utilize twin weapons (depends if it's twin blades, tonfas, steel fans), spear, umbrellas, giant bludgeon and gauntlets for fist-fighting. He can only carry two at once, however.
- The Musketeer: In Undying Moon, Fuma is able to wield various subweapons alongside his main melee ones, with muskets being one of them.
- Roguelike: Undying Moon follows this pattern instead of the exploration, semi-Metroidvania of the original. Each stage's map is auto-generated, and dying or restarting punts you back to the first stage. To get stronger, you need to gather materials, return to your estate through the portal after defeating a boss, which will at least keep your resources that you can use to strengthen yourself.
- Ninja: Getsu Renge is a kunoichi and a lot more blatant in that thanks to her clothing. Her boss fight also feature her spamming teleport and Ninja Log decoys. Being that this is a game where you go to Hell and fight off its legions, Renge doesn't bother too much with traditional ninja stealth.
- No Historical Figures Were Harmed: The main character is based on Fuuma Kotaro, mostly due to the legends that Fuuma Kotaro has wild red hair, along with Getsu Fuma's occasional Stock Ninja Weaponry.
- Nothing but Skulls: An improbable proportion of the overworld terrain is made of or covered with skulls. Other bones can be seen, but skulls are predominant.
- One-Winged Angel:
- Ryukotsuki does it twice, with its final form being large and tall enough to reach the top of the screen.
- In Undying Moon: Getsu Rando is fought twice, once in normal form, the other one is when he activates his own Demonization.
- Our Founder: Undying Moon shows that the original Getsu Fuma chose to seal himself as a statue in the underworld to keep its demons from invading the human world. He is referred to as "The Founder" in the in-game descriptions.
- Outside-Genre Foe: After slashing your way through demons, zombies and youkai, the Final Boss of Undying Moon is Amatsu-Tosu, a giant Octopoid Alien whose ship crashed in Hell.
- Pre-existing Encounters: Some enemy encounters are triggered by running into their sprites on the overworld, though in most places they're impossible to avoid.
- Samurai: Getsu Fuma's class, it would seem. Though that doesn't stop him from getting some shuriken, which brings this into Samurai Shinobi territory.
- Sealed Badass in a Can: Undying Moon shows that the original game's Getsu Fuma sealed himself in Hell to keep the demons away from the human world.
- Super Mode: Demonization in Undying Moon. If Fuma manages to hit enemies constantly without getting hit in return, he enters a state called Demonization, where he turns blue and gets a boost on attack power. Continuing to hit more without getting hit in return also upgrades the demonization form for even more boosts. Get hit and the mode go down a level.
- Stab the Sky: The ending.
And the beginning. And anytime you beat a sword-guarding boss. - Sword Beam: As the name might suggest, the Pulse Blade can fire off three energy waves.
- Theme Music Power-Up: During the penultimate boss of the game in Undying Moon, as Getsu Rando powers up with Demonization, Fuma picks up the Wave Sword from his ancestor (the first game's Fuma), activates his own Demonization and a remix of the Overworld theme from the first game becomes the battle theme music.
- To Hell and Back: Getsu Fuma goes to hell to fight Ryukotsuki, regain the family's lost swords and avenge his slain brothers. Played with in the respect that his victory allows his brothers to rest in peace, not bringing them back to life. And he goes for round two in Undying Moon because someone is breaking the seal again.
- Unexpected Gameplay Change: The 3D dungeon crawler segments in the original game, which is a 2D platformer with slight RPG Elements overall.
