“My hat is my friend. It helps me relax.”
– Koishi Komeiji

Koishi Komeiji's Heart-Throbbing Adventure (古明地こいしのドキドキ大冒険, Komeiji Koishi no DokiDoki Daibōken), also called KoiDoki (こいドキ) or KKHTA, is a fan-made Touhou Project video series, authored by a “Sentakubune” (洗濯船),¹⁾ that began on June 28, 2009.

The story begins with Koishi waking up on October 3rd, contemplating fishing and looking for a fishing rod, but she almost kills two people at Koumakan for one. Satori shows up to take Koishi home, locks her up at Chireiden, then returns to Koumakan the next day to apologize. Remilia sends her away, as they were being watched, but then Satori warns Patchouli about Koakuma which really agitates them.

Satori tries to kill Koakuma, but Remilia decks her in the face. Around the same time, Koishi tears down the wall locking her up, and chaos happens to break out in Gensokyo at 4:25pm on October 4th. Yukari and Reimu begin their investigation. Yukari checks Chireiden and Reimu checks Koumakan, while everyone tries to kill each other or has false memories. At some point, Satori walks home.

Yukari mistakes Koishi as the threat in Chireiden and kills her, then Reisen²⁾ reveals herself as their culprit and distracts her with Ran who had a bomb sewn inside her stomach. Yukari is executed and Reisen exits. However, Koishi's body becomes sentient, borrows Yukari's body, and she's pressured by Yukari to check in on Reimu. As for Reimu, she finds Koakuma and Udonge stops Reisen from ambushing her.

Meanwhile, Satori faces the souls being redirected to Chireiden, but the Watatsuki sisters suddenly appear before her and “kill” her for being a risk to their plans. We get a flashback sequence about the Lunarian invasion of 1982, where Satori was coerced into their “Moonlight Descent Ceremony” (月影降臨術, Tsukikage Kōrin-jutsu) plans and Koishi becomes traumatized enough to shut her eye.

By this point, it's revealed that the “Moonlight Descent Ceremony” would turn everyone into third eyes with the intent of achieving absolute world peace. Eirin also explains how the Lunarians achieved peace in the outside world by incidentally letting the madness soak Gensokyo, creating madness-inflicting moonlight, and hastily made a “rain of detoxification” to limit its effects before the Lunarians ousted her.

We're shown that the Lunarians warned the United Nations of an “imminent alien threat”, the day before the events of October 4th, 2022 took place. Reimu fights Koakuma, but Koakuma escapes with Patchouli on a Vishoka³⁾ ship. Kanako shows up to warn everyone at Koumakan of the upcoming war, leading everybody to the Hakurei Shrine where Toyohime wanted to make sure the barrier is broken.

They all lose and our protagonist is rendered helpless, then Kaguya curiously handed them a vial with “rain of detoxification” and leaves a hint about how to defeat a god. Night falls and the barrier is shattered at 6:59pm on October 4th, 2022, causing “Kaiju” to wreak havoc in the outside world. Of course, the Lunarians act as humanity's savior and sends Vishokas to kill them all, while Koakuma harnesses their powers.

Satori is taunted by Toyohime who reveals that Koishi isn't her sister, but somebody that she felt like raising. With the Kaiju count down to three, Yorihime kills Flandre, then Reimu and Marisa face Yorihime and both parties are killed. Toyohime isn't phased by her death as she's busy with blasting the moon's eye open, filling Tsukuyomi's wish, and turning everyone on Earth into third eyes.

We get a short scene of Eirin deciding to birth Kaguya's clone as neither of them want to return to the moon, but don't intend to upset Tsukuyomi. Seven years pass. The year is now 2029. Koishi visits a bakery on a snowy day in South Germany, then retuns home to cook for Yukari who has her own body. Yukari slaps Koishi in disgust and critiques Koishi's escapism. Surprisingly, these words finally gets through to Koishi.

Yukari blames herself for the tragedy that fell upon Gensokyo. Koishi suggests her to abandon her ego and heart, but Yukari believes her logic is selfish and forces Koishi to remember a conversation she had with Kokoro about what she loved about Gensokyo and what the real Koishi might've been like. From there, Koishi tears up and admits that she didn't want to see people's sadness and get hated for it.

In turn, Yukari concludes that Koishi closed her heart to feel special, and believes that Koishi had used her power to manipulate people's feelings selfishly. Koishi struggles to refute this as Yukari leaves the room. Ultimately, this conversation causes Koishi to use a glass shard to poke her third eye open, though it appears to cry blood in pain. Yukari is also seen crying outside of the room and the story ends there for now.

Most of the story takes place over the course of three days, October 3-5, but we're never given an explicit year. The Lunarians begin a 380,000 km journey to invade Earth in 1972,⁹⁾ slow down at 400 km away in 1982 while shredding Koishi's body,¹⁰⁾ then Koishi's rampage gets televised in the “early 1980s”¹¹⁾ where she gets a new body,¹²⁾ so we can extrapolate that the invasion is between 1982 and 1985.¹³⁾

From there, we are given a vague “40 year” estimate since the Lunarians have landed on Earth and begun reeducating the human race.¹⁴⁾¹⁵⁾ Depending on your estimate of the invasion, this means that the story began sometime between 2022 and 2025. At the end of the story, seven years have passed,¹⁶⁾ which places the somber “Bad Ending” scene between Koishi and Yukari somewhere between 2029 and 2032.

Toggle chart. (Spoilers included!!)

“Madness” (狂気, Kyōki) is a status effect that affects Gensokyo. It was an effect of the Lunarians removing the sorrows of mankind,²⁴⁾ as world peace is required for the ceremony, by trapping such emotions onto the dark side of the moon.²⁵⁾ However, this caused madness to soak Gensokyo and Eirin was dismissed before a proper solution was found,²⁶⁾ thus the Kaiju genocide is actually a Lunarian cover-up.

Following the Daiyousei experiment,²⁷⁾²⁸⁾ the Lunarians fully unleashed the madness onto Gensokyo which turned a portion of their population violent. It's important to note that it causes Cirno to misremember the night prior,²⁹⁾³⁰⁾ which is how a madness-afflicted Tewi believed she smashed Udonge's legs³¹⁾ when Udonge clearly has both legs.³²⁾³³⁾ As it currently stands, only the “rain of detoxification” can cure madness.

• The point of Sanae's backstory is that it was meant to subvert the then-popular Sadistic Sanae.
  • However, it does come off as unnecessary filler due to the fact that Sanae gets killed by Kogasa in self-defense, adding nothing to Suwako finding a dried-up Sanzu River with Kogasa.
• Koishi with Yukari's body was officially named “Koishi Yakumo” (八雲こいし), but the five-year gap may have led some artists to name the fusion “Yukari Komeiji” (古明地ゆかり) instead.
• Koakuma and Mamizou's eyecatches, around the 4:04 mark of Part 13,³⁴⁾ references Kaitei Shujin.
• Before the Great Hakurei Barrier shatters, Kaguya tells Koishi that “the only thing that can oppose 'god' in a world where everything is open… is a 'closed eye of love',” a reference to how Koishi has the title of “Closed Eye of Love” (閉じた恋の瞳, Tojita Koi no Hitomi) in Touhou Chireiden (2008).
• It should be noted that recent Touhou Project canon kinda ruins the story, like the series began when most fans still considered the Watatsuki sisters to be overpowered and unchallenged. With today's canon, Koishi's character has been expanded upon with her recent appearances, while Junko explicitly overthrows the Lunar Capital in Touhou Kanjuden which nerfed the Watatsuki sisters.
  • Sumireko didn't exist when Renko and Merry were shown in the present,³⁵⁾ so they had no way of knowing that Sumireko lived in the present with Renko and Merry in a near future.
  • Junko does exist in Koishi Komeiji's Heart-Throbbing Adventure, though she was simply found dead at the Hong Kong Special Administrative Region of the People's Republic of China.³⁶⁾³⁷⁾
• The scene where Yorihime tries summoning a Norse god but gets no response³⁸⁾ implies that Gods stopped existing, presumably because humans began worshiping the Lunarians instead.
• It's easy to take cheap shots and compare the story to Neon Genesis Evangelion, but do note that the Giant Impact (Impact Event) is a real-world scientific hypothesis that predates both of them.
• This is a joke question, but would the Soviet Union technically still exist? If the Lunarians had brought world peace in the 1980s, prior to the dissolution, and the communist ideology still exists as evidenced by the continued existence of the People's Republic of China, then…?
  • This would mean that, at the time of the Lunarian invasion, the Soviet Union's leader could've been Brezhnev (1982), Andropov (1982-1984), or Chernenko (1984-1985) when it occured.
  • Furthermore, we are never given the full name of “Germany” (ドイツ, Doitsu), so we cannot assess whether the Federal Republic of Germany and/or German Democratic Republic still exist.
• As a reminder, Yorihime's eyepatch covers her left eye. Not the right eye, like in Touhou LostWord.

Toggle chart. (Hey, what were those words before the Part 13 incident?)

• Almost Nothing Beats Doing Laundry on a Sunny Day on Niconico Douga - The official playlist.
  • Sentakubune on Pixiv - The creator. It's all art and you won't find much else.
  • Sentakubune on YouTube - New!
• Koishi Komeiji's Heart-Throbbing Adventure on Niconico Encyclopedia [JA]
• Koishi Komeiji's Heart-Throbbing Adventure on Pixiv Encyclopedia [JA]
• Koikoi's Heart-Throbbing Adventure on Moegirl Encyclopedia [ZH]
• Koishi Komeiji's Heart-Throbbing Adventure on Namu Wiki [KO]

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