Imperishable Night

Touhou Eiyashou ~ Imperishable Night (東方永夜抄 〜 Imperishable Night) is the eighth official game of the Touhou Project scrolling shooter series by Team Shanghai Alice. It is the third Touhou game to be released specifically for the Windows operating system. It was first released in the 66th Comiket in August 15, 2004.

Gameplay
Imperishable Night plays like a fairly typical vertically-scrolling danmaku shooting game, in which the player's character is always facing towards the top of the screen, shooting at anything that moves, avoiding and weaving between enemy bullets, and confronting difficult bosses at the end of a stage.

Quite a few details are unique to this game, including Last Spells - for an enemy, a Last Spell is a bonus Spell Card which the player can tackle without fear of losing lives/bombs. On the player side, Last Spells are secondary "bomb" Spell Cards, which last longer/do much more damage at the expense of two bomb stocks. There is a gauge which tracks how human/youkai (normal/focused) the player is, as well as a new "Time" system, which affects gameplay.

Time
Every stage has a time counter, which, despite what the name might imply, requires the player to collect a certain amount of "time points". If the player fails to collect the required amount by the end of the stage, the clock, which tracks the frozen time in Gensokyo, shifts one hour ahead. Otherwise, the clock only advances half an hour. The clock starts at PM 11:00; if the player ever reaches AM 5:00 in-game, the player is given a bad ending. Having to continue also advances the clock by half an hour.

Time points are collected via shooting down when playing as a human, or from grazing bullets when playing as yōkai. If the player loses a life, some time points are deducted. Also, when playing on difficulties Normal or higher, filling the time counter for a stage also unlocks the Last Spell for that stage's boss.

Human-yōkai pairs
Imperishable Night features a total of eight playable characters, in pre-set pairs (and later, individually). The pairs, one human and one yōkai, work in tandem: one person fires when unfocused, while the other pops in and fires when focused, with a reduction in movement speed. The two attacks can be drastically different. The individual characters do not have an attack change when focused, although the movement of player familiars (such as Remilia's) may change.

A gauge on the lower left corner of the screen keeps track of how human or yōkai the player is, and affects the player's score accordingly. The gauge, ranging from -100% (human) to 100% (yōkai), is determined by which mode the player uses more. When the player reaches ±80%, they can collect time orbs by hitting enemies (as a human) or by grazing against bosses and killing enemies (as a yōkai). Since it's important to collect as many time orbs as possible (to slow time and get high scores), the player should try to keep the gauge either below -80% or above 80%. Because Youmu Konpaku of the Netherworld Dwellers team is half-ghost, their gauges are adjusted accordingly (-50% to 50% solo, -50% to 100% as the team), and the minimum values for time orb collection are reduced. Youmu is the only character that can collect time orbs in both ways because of this.

Some enemies use familiars that change their vulnerabilities accordingly depending on whether the player is playing as a human or a yōkai at the moment. These familiars are completely invulnerable when the player switched to a yōkai, but at the same time these familiars cannot collide with the yōkai player and do not shoot bullets when the player is on top of them. The enemies' alternating vulnerabilities in this game draw comparisons with Ikaruga. Bosses may also change their standard attacks depending on the orientation of the player, usually firing slower bullets and/or homing bullets when the player is a yōkai.

Spell Practice Mode
The Spell Practice Mode is unlocked by beating the game with the normal ending (i.e. before the game time reaches 5:00 am). This feature allows a character/team to practice a spell card (bullet pattern) they have already seen in the Story Mode and Extra Mode. In this mode, players have only one life and cannot bomb, and is only able to clear a spell card by shooting down the boss before time runs out without being hit. Clearing spell cards here will show the creator's own comments on the spell cards or the characters associated with them.

Only available in the Spell Practice Mode are Last Words, which are typically the hardest spell cards in the game. These spells are earned by accomplishing certain feats such as beating the game using certain characters/difficulties or seeing/mastering a sufficient number of spell cards.

Story
It's the eve of the Harvest Moon Festival in Gensokyo when the youkai sense that something is wrong with the moon. It appears that the moon has been replaced by a fake moon that can never become full. In order to find the real moon before sunrise, the protagonists extended the night to make an imperishable night, and set out to find the culprit.

After minor skirmishes along the way, including a battle with a fellow culprit-seeker, the protagonists reaches Eientei, the mansion of the perpetrator. Once inside, they find that the mansion is guarded by the moon rabbit Reisen Udongein Inaba, whose ability can cause disorientation. From here, the team may either choose the path that leads to the fake moon conjured by Eirin Yagokoro, or the real moon, where the moon princess Kaguya Houraisan is hiding. It is then realized that the moon was swapped in order to sever the link between the earth and the moon to hide Kaguya from the lunar emissaries who seek to bring her back. The team then accepts Kaguya's "Five Impossible Requests" and fight until daybreak.

Having completed the Five Impossible Requests, the team is given another challenge by Kaguya in the Extra Mode: assassinate (again) her rival, Huziwara no Mokou.

Playable characters
Initially, the player must play with one of the four preset teams. After the player has beaten Kaguya with all four teams, then it is possible to play the characters individually. Playing as individuals instead of teams does not change the story.


 * Illusionary Border Team (幻想の結界チーム) — Ever since the moon got replaced with a fake one, Yukari hasn't been able to sleep. Because Yukari doesn't go out much, she had to rope Reimu in as a guide.
 * Reimu Hakurei (博麗 霊夢) — Attacks using homing amulets.
 * Yukari Yakumo (八雲 紫) — Attacks using needles and her shikigami Ran, who latches herself onto enemies.
 * Aria of Forbidden Magic Team (禁呪の詠唱チーム) — Annoyed at how the humans are oblivious to what's going on, Alice tried to solve the mystery by herself, but she ended up bribing Marisa with books to make her tag along.
 * Marisa Kirisame (霧雨 魔理沙) — Attacks using magic missiles.
 * Alice Margatroid (アリス・マーガトロイド) — Attacks with her doll, Shanghai, who fires a straight beam.
 * Visionary Scarlet Devil Team (夢幻の紅魔チーム) — Remilia sent Sakuya to investigate, but Sakuya fails to notice anything wrong to investigate. Remilia then went out to deal with the incident herself, with Sakuya following behind.
 * Sakuya Izayoi (十六夜 咲夜) — Throws her knives over a wide area.
 * Remilia Scarlet (レミリア・スカーレット) — Can station her shots in one place while she moves elsewhere.
 * Netherworld Dwellers' Team (幽冥の住人チーム) — Yuyuko and Youmu both sensed something was wrong, but Yuyuko wasn't too confident in Youmu to let her investigate by herself, since someone who could manage to seal the real moon away must be very powerful, so both Yuyuko and Youmu set out.
 * Youmu Konpaku (魂魄 妖夢) — Fires with her ghostly half, which acts as an option that fires opposite to her move direction.
 * Yuyuko Saigyouzi (西行寺 幽々子) — Her butterflies have a wide attack spread.

Boss characters

 * Wriggle Nightbug (リグル・ナイトバグ) — Stage one mid-boss and boss, a firefly youkai who happens to be in the way.
 * Mystia Lorelei (ミスティア・ローレライ) — Stage two mid-boss and boss, a night sparrow preying on humans.
 * Keine Kamishirasawa (上白沢 慧音) — Stage three mid-boss, boss, and Extra stage midboss. The protector of the Human Village who turns into a hakutaku during full moons. Because the extra stage takes place after the incident, Keine returns as the midboss of the extra stage in her hakutaku form.
 * Reimu Hakurei — Stage four boss when playing as Marisa/Alice or Sakuya/Remilia. Reimu is looking for the one who stopped the passage of time.
 * Marisa Kirisame — Stage four boss when playing as Reimu/Yukari or Youmu/Yuyuko. Like Reimu, Marisa is searching for whoever she thinks is the one lengthening the night.
 * Tewi Inaba (因幡 てゐ) — Stage five midboss, a youkai rabbit who has taken residence in Eientei.
 * Reisen Udongein Inaba (鈴仙・優曇華院・イナバ) — Stage five boss, a rabbit who deserted from the moon, now a disciple of Eirin.
 * Eirin Yagokoro (八意 永琳) — Stage six mid-boss and boss if you choose path A or Stage 6 midboss if you choose path B. A master pharmacist who, long ago, produced the elixir of life for Kaguya, causing Kaguya to be exiled from the moon.
 * Kaguya Houraisan (蓬莱山 輝夜) — Stage 6 boss if you choose path B. The princess from the Tale of the Bamboo Cutter, originally from the moon but now lives her life in Gensokyo in recluse from the lunar emissaries who want her back.
 * Huziwara no Mokou (藤原 妹紅) — Extra stage boss, a girl who, by some chance, swallowed the elixir of life and became immortal. She held a millennium-long grudge against Kaguya for humiliating her father when he was seeking Kaguya's hand in marriage. Unable to die by any means, she and Kaguya kill each other and reincarnate on a daily basis.

Development
The sole creator of the game, a man who goes by the pseudonym ZUN, had long wanted to make a shooting game where the player can switch between two characters easily during the game, since he perceived that there wasn't many games with such a system. The idea for Imperishable Night started with this desire, and the plot was written later to justify this system. He has had the idea before the making of Embodiment of Scarlet Devil, but he felt that having playable characters that were not previously introduced would be unnatural. Thus he decided to make the system in Team Shanghai Alice's third game, Imperishable Night, so he could introduce new characters in the first and second game.

ZUN found it particularly difficult to find a youkai character to pair Reimu and Marisa with. In the end, ZUN picked Alice from the pre-Windows games to be Marisa's partner since he thought Alice was a "Youkai version of Marisa", and thus reintroduced her in Perfect Cherry Blossom. Yukari was selected to be Reimu's partner because their personalities were similar and would make sense to be together.

Related media
Touhou Bōgetsushō (東方儚月抄) is an extension of the story in Imperishable Night, split into three parts, each carried by a different Ichijinsha magazine. The main component, Silent Sinner in Blue, is a manga serialized in the monthly Comic Rex; it is through Silent Sinner in Blue that the main plot progresses. Cage in Lunatic Runagate is a novel being serialized in the quarterly Chara Mel; it centers on the viewpoints of the characters around the story. Finally, The Inaba of the Moon and the Inaba of the Earth (月のイナバと地上の因幡) is a lighthearted yonkoma focusing on Reisen and Tewi Inaba. The plot of Touhou Bōgetsushō overall revolves around the disturbances on the lunar capital, Yukari's plans to invade the moon, and Remilia's rocket trip to the moon.

Ichijinsha sought ZUN for this venture before he started to work on Mountain of Faith, and ZUN once had thoughts to make the manga about the upcoming game. However, as Mountain of Faith progressed, ZUN decided that he should base the story on something that Touhou fans were already familiar with. He turned to Imperishable Night because he felt the game did not provide much room for character development despite having such a rich cast. With the three-part media blitz, ZUN hoped to expand on the characters' inner thoughts.