Five great gates of Ouka be, Name them here for all to see; Sieryu, Byakko and Genbu Kirin and Suzaku be there too; At Heaven’s gate twin keys you need; At Earth’s gates, bows the Divine Steed; The soul is born as the Yang moon whirls The body is born as the Yin moon twirls The twin moons make a mighty hum From the watery moon, it doth come.
Liju Liu and Liji Lee. The Forbidden Poem
An Action RPG by Climax Entertainment designed for the PlayStation Portable, it is known as Tenchi no Mon in Japan and Key of Heaven in Europe. It was released in the US in December 2005 and in Europe in March 2006.It is heavily influenced by Asian culture as a whole, especially the Chinese Ssu Ling, on which four of the five clans in the game are based.
This game exhibits examples of:
100% Completion: One needs to collect all of the bugei and kenpu scattered about Ouka in order to achieve this.
Chekhov's Gunman: Li Yin and Lu Yan. They are the twin keys referred to in the fifth line of the Forbidden Poem. Sadly, that means they cannot exist once the Toshitetsu is activated to release Banko.
Dark Is Not Evil: As seen with the Ruthless vs. Righteous clans. It is pointed out in-game that the Ruthless clans, Genbu and Byakko, are not explicitly evil; rather, they simply use a different style of bugei and chi arts.
It's hinted that the Righteous and Ruthless clans represent the yang and yin forces, with the latter being the more 'destructive' force. Hence the Ruthless' powers of Chi Disruption.
Also, Yen Lan. She's on the antagonist's side, but she's really not specifically evil.
The complimentary system plays this straight. It runs in a cycle that gets stronger the longer you chain the cycle. This is especially important with your Freestyle Bugei.
The charging system double subverts this. In order to create the strongest attack, you have to make sure your first set of kenpu is weak against the element of your opponent. Your last kenpu has to be strong against your enemy's element.
I Want My Beloved to Be Happy: The game adores this trope. Yen Lan to Hohaku is the most prominent example, but also applies for Sui Lin (to Shinbu), Xiuk Yu (to Lei Gai), and arguably Soh Yu to Jok Xiu.
The Legend Of Chekhov: The Forbidden Poem. It's that important to the game, even though NPCs will usually try to stay away from information regarding it.
Lost Tribe: Uzo and Muzo, the last of the Mt. Gokuho faction.
Minored In Ass Kicking: Ho boy, Professor Seidatsu. He's your worldly mentor, even teaching Eigen after Genra's attack. Later on, Uzo and Muzon take him hostage in Gokuho Island. But they never realized that he's one of the masters of the San'yuan and proceeded to break out of his bonds and kick the shit out of the bandits.
No Export for You: Due to horrible sales, the sequel (really a prequel) has never been released outside of Japan.
Palette Swap: For the generic field battles, the 'disciples' are identical save for their uniform color.
You Can't Go Home Again: The primary motivation for Lord Gikyo's antagonism is because he is rapidly approaching 300 years and his chi techniques cannot sustain him any longer, and thus needs to return to Seima. Unfortunately, he really can never go home again because Densei killed him before he had the chance to activate the Toshintetsu and open the gate to Seima.
You Killed My Father: Shinbu finds out that both Uzo and Muzo attacked both his mother and father, killing his mother and taking his father prisoner on Gokuho Island. Doubles as his Crowning Moment of Awesome as he gives both of them an epic ass-kicking the third time he fights them.