Nanatsu no Hikan

Nanatsu no Hikan (七つの秘館, Literally: Seven Mysterious Mansions) is a three-disc adventure game produced by Shibusawa Kou. It is one of the adventure game from Koei to feature 3D models for its characters. The game is set in a contemporary setting, roughly taking place in the mid or late nineties. Even so, there are several historical references within the puzzle solving sections of the game.

The game's story was written by Kageki Shimoda, a novelist, picture book writer, and entertainer. Shimoda also acts out live action segments played throughout the game to give clues to the player. Ichirō Nagai provides the sporadic narration.

Nanatsu no Kikan was released a second time on the Sega Saturn to be coupled with Myst. The two games were advertised as an adventure pack and were available for purchase in Japan since March 28, 1997. An action-adventure sequel, Nanatsu no Hikan: Senritsu no Bishou, was released for the Dreamcast on January 20, 2000.

Plot
One day, a young man from a high-classed background named Ippei is called to the office of his uncle, Shujiro. Shujiro is the current head of his family who is concerned about seven mansions left behind by the last clan head (Ippei's grandfather, Shuhei). The seven mansions were strangely built in a Big Dipper formation on a remote island and have never been fully explored by the family members of Ippei's generation. Shujiro wants to create a resort where the mansions are located yet feels that there is a marvelous treasure or secret left behind by their ancestors. Too aged and busy to explore the buildings himself, Shujiro asks Ippei to unlock the secrets for him. He gives the eager youth a key to the first mansion and a riddle left behind by Shuhei. Before Ippei leaves, Shujiro warns him that there are three dangerous people already on the island apparently searching for whatever value left on the island.

As Ippei explores each mansion, fragments of his family's history are slowly revealed to him. His family founder is tied to the Takeda family, specifically from Shingen and Katsuyori's branch. After the latter's fall, the family founder ran away from the Takeda hunt issued by Oda Nobunaga and sought safety in the area of the seven mansions. Ippei's grandfather fashioned the seven mansions in honor of the Takeda clan, the characteristic four diamond crest and references to the Twenty-Four Generals being scattered within each mansion's dwellings. After discovering their actual heritage, however, Shuhei learned a dark side to their family and built the seven mansions to hide it from curious treasure hunters. Ippei's job is to learn what it is before it is lost forever.

Gameplay
Since the game is first person, the player sees through Ippei's eyes the entire game. The camera angle is fixed and cannot be changed unless the player chooses to pivot or move Ippei. To move him, simply press up on the directional pad. Choosing left or right makes him turn in their respective directions and pressing down has him perform a quick about face. Ippei is limited to walking in whatever direction he is facing, moving straight one screen (or for Ippei, approximately a few steps) at a time. Hallways might take several taps for Ippei to reach the opposite end. The arrows located in the upper left hand corner indicate which paths are available for exploration. Highlighted green arrows are fine and dull gray ones are prohibited. Paying attention to the status of these arrows might save the player time for determining locked doors.

There are no combat controls in this game, but Ippei's health is still a concern. Traps and other destructive mechanisms may hurt him if he isn't careful. The player can visually check the status of his health by the stick figure positioned underneath the aforementioned arrows. An Ippei in sublime health has an orange stick figure with both his arms raised. The stick figure's stature gradually drops as Ippei gets hurt, lowering to his knees whilst colored violet in critical stages. A note of caution on traps: some of them may instantly lead to a game over when activated.

Pressing opens a text menu for Ippei's actions; to cancel out of this menu, press. Options in the action menu from right to left are:
 * Use Item - grabs an object from Ippei's inventory to use on the screen he is facing. Occasionally, he will combine two items automatically to better serve his purposes.
 * Investigate - looks at anything in front of him. This maybe needed to discover more items or clues for solving a puzzle. If there is nothing he finds interesting, he will inform the player.
 * Take - often used for items Ippei finds and needs to bring with him. If there is nothing he can take, he will inform the player and instantly exit out of the action menu.
 * Move - Ippei shoves or moves an object from its spot. Depending on the object, he may touch them to find more clues. For switches, levers, or buttons, this is the action he will need to take to activate them. He won't move objects that are too heavy for him.
 * Talk - talks to anything in front of him. Ippei needs this feature when facing portraits of his grandfather.
 * Look at Item - observes artifacts in his inventory. Ippei will read retrieved scrolls or documents when they are selected. At times, he will also observe a message inscribed onto one of his items.
 * Visit Mansion - before entering the door to another mansion, Ippei has the option to turn back and explore one of the mansions he previously visited. The options are limited to the mansions on the particular disc.

Tapping lets the player choose from another menu. From right to left, these options are:
 * Status - lets the player review Ippei's health and location. His family name, birth date, and current time can also be reviewed here.
 * Memory - the saving option for both memory cards. A maximum of fifteen slots is available. If the player doesn't want to commit to saving on their cards, they can perform a quick save at their current location.
 * Recall - the loading option. Loads anything from the current disc the player is using. Choosing data from another disc will bring up a refusal message from the game.
 * Settings - allows adjustment to message speed and audio settings for the voices. Players may choose to hide the icons for available directions or health.
 * Quit - shuts down game entirely without saving current progress.

When a disc is cleared, the player needs a save slot dedicated to it. Loading from this save is mandatory for the other disc. There is no in-game disk swap option, meaning that the player will first need to place the disc they want into their module and manually reset to play from their desired disc.

Characters

 * Ippei (一平)
 * Voiced by Hikaru Midorikawa
 * The main protagonist and the player's character. At the start of each game, the player can change his family name and his birth date to their liking. If the player chooses the default family name, it will input Tobishima (飛島) for them. Ippei is clueless of his family's history yet is fascinated with unlocking the secrets held within the mansions. When his lover is kidnapped, Ippei is driven to solving the mansions as quickly as possible to reach her in the final one.


 * Reina (玲奈)
 * Voiced by Mariko Kouda
 * Ippei's lover who is a member of the Shirakawa family. For reasons unknown to her, the Shirakawa family have long been friends with Ippei's family. Thinking that the mansions maybe related to their family history, she decides to accompany Ippei's search. Before he finishes solving the first mansion, she is kidnapped by two men targeting Ippei and is held prisoner in the last mansion.


 * Suzuko (鈴子)
 * Voiced by Yuri Amano
 * A mysterious girl who according to Ippei "looks to be about fifteen years old". She wanders the island and appears to support Ippei at various mansions. She holds feelings for the young man, but adventurous Ippei is oblivious to her affections. When she feels incapable of offering protecting Ippei protections, she asks her Shiba Inu friend, Chichiro, to save him.


 * Madoka (まどか)
 * Voiced by Rika Fukami
 * One of the three villainous figures of the story, Madoka is a buxom woman who is hellbent on having revenge on Ippei and his family. She hires two goons, Akashima and Kurotani, to do the dirty work for her. Implied to be a psychic, Madoka watches Ippei's progress from her crystal ball and waits for him to arrive at the seventh mansion. The reasons for her grudge are gradually revealed as the player solves the mansions in the game.


 * Akashima (赤島)
 * Voiced by Yukimasa Kishino
 * Muscled brute who is all about brawn, Akashima is a bald man who works under Madoka. He doesn't care much for serving his pushy boss, forming a brotherly bond with Kurotani. Though easy to deceive, he is furious with anyone who tries to cross him. Akashima swings around an iron ball and chain when he tries to attack Ippei.


 * Kurotani (黒谷)
 * Voiced by Keiichi Nanba
 * A slender man who wears dark glasses, Kurotani is a sly individual who is known for his habit of humming on the job. Like Akashima, he doesn't like Madoka or her demands to merely steal a key from him. Instead, Kurotani plans to kill the youth and take the family treasure for himself. He convinces the disgruntled Akashima to follow his scheme before Ippei reaches the seventh mansion. When he attacks Ippei, he prefers to shoot from afar with a crossbow.


 * Fourth Head Shuhei (周平)
 * Portrayed and voiced by Kageki Shimoda
 * Ippei's grandfather who ordered the seven mansions to be built. Before he died, he left portraits of himself to talk to Ippei directly. He must have been a person of formidable foresight since he specifically addresses his grandson during these recorded messages.


 * Founder Kihei, Second Head Yataro, Third Head Ginjiro (喜兵衛, 弥太郎, 銀次郎)
 * Portrayed by Kazuo Tokumitsu, Hitoshi Kusano, Tomitoku Shu
 * Previous heads of Ippei's family line. Their images are preserved as portraits throughout the game and do not reanimate like Shuhei's images. Ippei gradually learns the truth of each head as he explores each mansion.

Stages

 * First Mansion
 * A mansion designed with an European touch, the place has a playing card motif throughout its corridors. Its floors are decorated with a checker board pattern and mahogany wood is prevalent for the furniture and doors. Knights in armor and portraits of kings and queens decorate the hallways. When exploring the library, Ippei breaks the fourth wall when he finds a Nanatsu no Hikan guidebook. He dismisses the book as pure nonsense and decides to leave it be.


 * Second Mansion
 * Inspired by the long history of China, this mansion is filled with statues of the wizened Shi Huangdi and the beautiful Yang Guifei. Armed statues protect the walls of Shi Huangdi and an arrow trap is triggered to fire at those who enter Yang Guifei's room. The second floor of the area includes portraits and statues of Liu Bei, Guan Yu, Zhang Fei, and Zhuge Liang. In order to proceed through the area, Ippei needs to find and locate three items attributed to the strategist and present them to his statue.


 * Third Mansion
 * Shaped and built like a traditional Japanese hut, this three floored mansion is filled with statues of various wild animals. When he explores the room of a black goblin statue, it fiercely embraces him and shifts the mansion to reveal a hidden second floor. These animals hold the keys revealing the Takeda history to Ippei, specifically targeting the famed Twenty-Four Generals. The main puzzle of the mansion is pressing specific name tablets dedicated to the generals.


 * Fourth Mansion
 * A mansion filled with clocks, this place is built with inspiration from Heidi's Years of Wandering and Learning, a story about a girl within the Swiss Alps. A key part of the mansion's design aside from the constant ticking of clocks is a scorpion inscribed on the clocks. Shuhei designed the mansion to give off the impression of a fantastic adventure that must be explored alone.


 * Fifth Mansion
 * Dedicated to the masters of classical music, the fifth mansion is filled with grand pianos and a giant organ. The windmill nearby the mansion's walls is built to play music as it turns. Compositions from Beethoven, Mozart, Chopin, Liszt, and Schumann can be found and played at select player pianos. Ippei must play specific songs to unlock the doors and hallways.


 * Underground Passageway
 * The gap of land bridging the entrance to the other mansion. Ippei encounters strange creatures and traps inside.


 * Sixth Mansion
 * Simplistic yet classy, this mansion is dedicated to the Greek and Roman mythology. A lion guards the front door and a Sphinx statue faces those who enter. Statues of Socrates and Hermes stand nearby and the walls are decorated with various scenes from the two civilizations (including but not limited to images depicting the birth of gods, a reference to Agrippa and the Battle of Actium, and Brutus not knowing the sands of the Nile).


 * Seabed Cave
 * Escaping through another underground path and swept by a river underneath the first mansions, Ippei uses a boat to row his way onto the seabed floor and walk his way to the entrance of the seventh mansion.


 * Seventh Mansion
 * Unlike the other mansion, this place isn't made with a particularly strong theme in mind. It is shaped and modeled after a school campus yet is guarded with by Medusa and harpy statues that shoot laser beams at interlopers. Inside its halls, a bust of Nobunaga and a statue of Venus stand within the house's main hall. Adorning the walls of the mansions are paintings dedicated to Napoleon Bonaparte. Beside these paintings are name plates dedicated to the characters in Shingen's trademark Fūrinkazan.


 * Northern Island
 * Traveling by boat off the seventh mansion's coast, Ippei finds the treasure his grandfather sought to hide.

Image Song

 * Love Groove
 * Performed by Megumi Watanabe

Allusions

 * If the player plays the turntable in the oath brothers' room, an orchestrated version of the menu theme from the first Romance of the Three Kingdoms plays for a few seconds. The same song acts as a prominent musical motif throughout the series, easily heard in the "A Kou Shibusawa Production" splash screen for the series's eleventh title. The three statues are also not 3D models and are rendered as images. Their portraits vaguely resemble the art style featured in the fifth title's cinematics. Listening to the song in this game greatly restores Ippei's health.
 * Replicas of weapons used by Liu Bei, Guan Yu, Zhang Fei, Dian Wei, and Xu Huang in the novel appear. Two other noteworthy mentions include the mythical Seven Star Sword from Cao Cao's botched assassination attempt and a three bladed trident used by Ji Ling. Giving the oath brothers their weapons is needed to solve a puzzle in the second mansion.
 * Yang Guifei has a few subtle mentions in item descriptions within Nobunaga's Ambition and the online adaption of Uncharted Waters. Socrates also makes a rather anachronistic appearance in the latter title.
 * Although Koei has not made a simulation game directly related to the time period, Julius Caesar appears as an optional officer in Romance of the Three Kingdoms VII. On a somewhat related note, Creative Assembly Limited's strategy game, Rome: Total War, was localized by Koei in Japan.
 * Exploring Egyptian tombs and the Sphinx are events that happen again in Enigma.
 * Classical music is one of the prevalent themes for Ruby Party's Kin'iro no Corda series.
 * The three portraits of the Takeda Twenty-Four Generals appearing in this title are lifted directly from the sixth Nobunaga's Ambition title, Nobunaga no Yabou: Tenshoki.
 * Napoleon is the star character of L'Empereur.