The following are my own interpretations and are not official.
Album name
The title is pronounced as Tetra / テトラ which is the Greek prefix pertaining to “four”… But there are only three people in Hifuu Club this time, and the name is just a triangle? Read on.
Vocalist roles
- めらみぽっぷ (Meramipop) = Merry
- 紫咲ほたる (Hotaru Murasaki) = Renko (track 5)
- nayuta = Sumireko (track 4)
Burnt letter
The top half of this burnt letter was posted by RD on Twitter shortly before announcing the new album. Both the top and bottom halves can found on the secret webpage (through the QR code in the CD booklet).
English translation, top half (CLICK TO EXPAND)
This is me speaking to myself, in a corner of this dying world.
Our universe is destined to perish momentarily.
And the culprit … there’s no mistake, it’s “them”.
It all started with a message.
A message of unknown origin, which is contained by this disc. I did not know where or whom it was from.
Of course I couldn’t know, because it was a message from another universe.
A universe above ours - a higher-layer universe.
What the message said was truly astounding.
There are other universes residing in a layer above ours.
There are also other probability universes in the same layer as our own (!).
And this disc could let us see the other universes in the same layer as ours.
But what it showed us -
Were worlds being contaminated, eroded, and destroyed by “them”.
I’m sure it was “them” who caused
the neighbouring universes to become like this.
And when I realised this, “they” are already here in our universe.
I wasn’t able to play around with this message.
That is to say, our sound will not reach anybody else.
The only thing we can do, is to watch over while sending this message to lower-layer universes.
Please, let this message reach universes where “they” don’t exist,
before “they” - the “Hifuu Club”, destroy all the universes.
English translation, bottom half (CLICK TO EXPAND)
…… but actually, we know.
When this message reaches you… it would already be too late.
I’m sure something like this will also happen to the next universe.
Our neighbouring universes are already contaminated.
Because well, this message itself is aimed at the “Hifuu Club”, isn’t it?
If that’s the case, we are already contaminated. We are no longer able to think of a universe without the “Hifuu Club”.
Those who made this message in the first place, who knows what they were thinking?
Ah, then let’s just
Spread it!
Spread it far and wide! Let the Hifuu Club reach many, many, many, many more universes!
The Divine Message
RD also posted this video on Twitter, which is actually Track 1 of the album i.e. The Divine Message. This seems to be a message from Hifuu Club (consisting of three people) which mentions their grand project named “Project Tetra”.
SPOILER (CLICK TO EXPAND)
In the source code of the secret webpage found through the QR code in the album booklet, there is a hint to reach another secret webpage which contains the uncorrupted Divine Message audio (i.e. Activity-log-21-12-12). This also explains why the Hifuu Club has three people, but the project is called Tetra, the Greek prefix for “four”. (tl;dr: you are the fourth person).
According to the credits on BK, the whole text is read by Merry = Meramipop.
By the way, the backing music sounds very similar to Gymnopédies (shudders in The Gymnopédies Never End…).
Activity-log21-12-12 By-ear transcription (CLICK TO EXPAND)
あ、あ。これ、もう音入ってる？
あ、そう？オッケー、始めるね？
え、私たちは、多世界宇宙知的生命体探査同好会の、ああ…
私は、メンバーのハーンといいます。
え？なに？ええ！やっぱりその名前にするの？
だってなんか恥ずかしいだもん！え？すみちゃんまで？
わかった！わかったから！
え、私たち、多世界宇宙知的生命体探査同好会「秘封俱楽部」より、
メッセージを発信します。
最近の私たちの世界の科学では、
宇宙の存在形態についての研究が発展しています。
宇宙に無限の過去があることが証明されたのは、六十年ほど前のこと。
最新の研究では、宇宙の姿は過去にも未来にも無限であり、
その存在、可能性も一つではないということは判明しました。
これはつまり、自分たちが存在する宇宙とは、
別の宇宙が存在しているという可能性を意味します。
しかし、それにもかからわず、私たちの世界では、
別の可能性宇宙に向けたコンタクトは積極的に進められていません。
これは非常に残念なことです。もったいないことだと思われます。
そこで、私たち秘封俱楽部は他の可能性宇宙に向けて、
独自にメッセージを発信してしまおうと考えました。
このメッセージに危険な意図はありません。
また、このメッセージは選ばれた特定の宇宙に
届くように設定しているわけではありません。
もしかしたら、どこにも届かずに失われてしまうかもしれません。
けれど、上位宇宙から下位宇宙へのメッセージとして、
あなたに届くといいなと思います。
あなたの宇宙はどうですか。
私たちはあなたに何もできませんし、あなたの助けになることもできません。
けれど、この小さな贈り物が届いたら、素敵だなと思います。
この無限に広がる可能性世界から、私たちの声を掬い取ってもらいたら、
きっと、素敵な気持ちになると思います。
これは私たち三人と、媒介者であるあなたによる、
宇宙を跨いだ壮大なプロジェクトです。
よってこれを「プロジェクト・テトラ」と名付けました。
このメッセージを受け取ったあなた、
是非、私たち「秘封俱楽部」の存在を、もっと広めてください！
それでは。
Activity-log21-12-12 English translation (CLICK TO EXPAND)
Ah, ah. Is this thing on?
Is that so? OK, I’ll start.
Eh, we, a Search for Multiverse Intelligent Life Association, ah…
I am Hearn, one of the members.
(Very quietly) Wait, really? Are we actually going to use that name?
It’s so embarrassing! What, Sumireko you agree?
OK, OK! Fine!
We, the “Hifuu Club”, a Search for Multiverse Intelligent Life Association,
are transmitting this message.
In recent years, in our scientific world,
there has been developments on the research of the form of existence of the universe.
About sixty years ago, it was proven that there exists an infinite past in the universe.
The latest research has shown that the universe does not only have an infinite past,
but also an infinite future, and that there is more than one way in which it could exist.
That is to say, the very existence of our universe,
means the possible existence of other universes.
Nevertheless, our world
is not actively trying to contact other universes.
This is very disappointing. What a waste of opportunity!
This is why we, the Hifuu Club,
thought we should send a message to other possible universes on our own.
We mean no harm by this message.
Also, this message is not set to be
delivered to a specific universe.
Perhaps it will become lost, without ever reaching anywhere.
But I hope it will reach you,
as a message from a higher-layer universe to a lower universe.
What is it like in your universe?
We can’t do anything to you, nor can we help you.
But I think it would be wonderful if this little gift reached you.
What a wonderful feeling it would be,
to scoop up our voices from this infinite world of possibilities.
This is an epic cross-universe project
between the three of us and you, our intermediary.
Therefore, we named it “Project Tetra”.
You who have received this message,
please spread the word about our Hifuu Club’s existence.
Goodbye.
The System
As explained in the System Manual in the CD booklet, people from U0001-9134845-120368896 received a divine message from their saviour - a higher-layer universe, and they built a System to spread Project Tetra further downwards. The System can be passed down to lower universes, and is only able to scan for possible universes in the same layer as itself.
The System IS this CD album, evident from the text on the disc: PROJECT TETRA DATA DISC U0001-9134845-120368896.
My theory on the universes SPOILER (CLICK TO EXPAND)
- U0000-0000000-000000000: Hifuu Club transmitted a message to lower universes.
- U0001-9134845-120368896: the message was scrambled before being received by this universe. People in this universe misintepreted the message segments, and thought the higher-layer universe was going to save them (due to hearing words like あなたの助けに (be your help), and only hearing the first half of 掬い取って (“scoop up”), which sounds the same as 救い (“salvation”)). They even constructed a System to spread Project Tetra, as a way to repay their saviour’s kindness. The System is also able to scan many universes within the same depth layer.
- U7730-■■■■■■■-■■■■■■■■■: People in one of the universes in this depth wrote the burnt letter mentioned above. After observing their neighbouring universes die in many different ways through the System, they thought the Hifuu Club was a contamination that destroyed universes. They wrote the letter to warn lower universes, but knew this was futile and decided to spread this contamination further downwards anyway.
- U7731: I think this is the layer our universe, as the System can only search for the other universes in the same layer as it is currently on i.e. ours. The other album tracks are from our neighbouring universes. Also, track 10 is possibly the most close-to-original rearrangement from RD, maybe this is hinting that track 10’s universe is the one where the real Touhou Project, and thus we, exist.
English Translation of the System Manual (CLICK TO EXPAND)
For new users of this system:This system is designed for the Most Exalted Project.
The purpose of this complex system is to observe possible universes, and to spread the Divine Message.
When this System is running, it is able to collect the Possibility Depth Layer and Possibility Coordinates of the Universe that the System is currently in.
Afterwards, it is able to collect the states of neighbouring Possibility Universes on the same Possibility Depth Layer, and to output information on those universes.
≪The Meaning of the Existence of this System≫
We of the universe U0001-9134845-120368896, on the date 20■■-12-12, have received a message from a higher-layer universe.
The message was fragmented, but it clearly showed the intention of the higher-layer universe to lend their help and save our universe.
We admire this noble idea, therefore we have designed this System, in order to repay the kindness of those who bring salvation upon us, as much as we possibly could.
The purpose of this System is to spread Project Tetra even further,
As well as to observe the neighbouring universes as they bask in the coming salvation [Normal output failed. Error Code: 0x0ff00a77843 Please contact the system administrator.]
≪! Attention !≫
The message can only be send from a higher-layer universe to a lower-layer universe.
≪About the Possibility Universe Address≫
The address of a Possibility Universe is formatted as below:
① ② ③ UXXXX-XXXXXXX-XXXXXXXXX
① The Possibility Depth Layer where this System currently resides.
This number increases every time this System is passed down to a lower universe.
② The serial number of the Main Coordinates.
③ The serial number of the Subset Coordinates within the Main Coordinates.
The differences between the Possibility Depth Layer, the Main Coordinates serial number, and the Subset Coordinates serial number, show the extent to which the possibilities of two universes differ.
≪! Important !≫
[HEAVILY CORRUPTED TEXT]
The last part of the manual is heavily corrupted, both the image, and the text itself which turned into mojibake.
Attempt at recovering the last part of System Manual (CLICK TO EXPAND)
Same process as how I unscrambled the cover art hover text, see section below for details. Blue text = unsureCorrupted text:
荳倶ｽ榊庄閭ｽ諤ｧ螳?ｮ吶↓縲檎ｧ伜ｰ∽ｿｱ讌ｽ驛ｨ縲阪′｢蜀吶＆繧後■■■■■繧ｷ繧ｹ繝?Β縺ｮ險ｭ險医?逶ｮ逧?〒縺吶′■縲∝ｿ?★螳溯｡後＆繧後∪縺吶?
Uncorrupted text:
Cover art hover text
Hovering over the cover art in the album page reveals the following text:
Tl;dr: this sentence:
is the corrupted form (mojibake) of the sentence:
which translates to:
This might be referring to the preceeding text /封?楽&%, saying it could only be “spelt” as 秘封俱楽部 (Hifuu Club). The Divine Message is an audio message so it is impossible to know which kanji were used.
How to work out the original, a.k.a. detail for nerds (CLICK TO EXPAND)
I feel that most of the corruption in this paragraph was added manually, but one sentence stands out as a typical Mojibake（文字化け） , which occurs when displaying UTF-8 encoded text in Shift-JIS:
Unfortunately, mojibake is not completely reversible, but chucking this into a mojibake inverter revealed an almost coherent sentence:
To solve the rest of the content, firstly converting the corrupted text into hex:
e3 81 93 e3 82 8c e4 bb a5 e5 a4 96 e3 3f e7 b6 b4 e3 82 8a e3 3f e8 80 3f 81 88 e3 82 89 e3 82 8c e3 82 8b e3 81 a0 e3 82 8d e3 81 86 e3 81 3f
Shift-JIS uses one or two bytes to represent one character (Shift-JIS lookup table), whereas UTF-8 uses variable number of bytes. However:
- knowing the original text is probably all in Japanese, there should be 3 bytes per character in UTF-8, and the first four bit of each character should be 0b1110 = 0xE.
- 0x3F in Shift-JIS is the question mark, which represents a character not found in Shift-JIS, so it could represent either one or two unknown bytes in the original text. Also 0x3F would not occur in any bytes in UTF-8, as the bytes should begin either with 0b1110 = 0xE (first byte), or 0b10 (subsequent byte).
This led to me dividing the hex up in threes, and replacing 0x3F with one or two missing bytes as appropriate. Let’s also fill in the characters deobfuscated by the mojibake inverter:
e3 81 93 こ e3 82 8c れ e4 bb a5 以 e5 a4 96 外 e3 ?? ?? e7 b6 b4 綴 e3 82 8a り e3 ?? ?? e8 80 ?? ?? 81 88 e3 82 89 ら e3 82 8c れ e3 82 8b る e3 81 a0 だ e3 82 8d ろ e3 81 86 う e3 81 ??
More observation: characters beginning with 0xE3 represents Unicode code point U+3???, and is likely a hiragana. The one beginning with 0xE8 is a kanji.
Now, guess work:
?? 81 88: The only sensible first byte would be 0xE3, which results in the Hiragana え. Other 0xE? yields very uncommon characters.e8 80 ??: The only possible range of characters is U+8000 to U+803F: 耀 老 耂 考 耄 者 耆 耇 耈 耉 耊 耋 而 耍 耎 耏 耐 耑 耒 耓 耔 耕 耖 耗 耘 耙 耚 耛 耜 耝 耞 耟 耠 耡 耢 耣 耤 耥 耦 耧 耨 耩 耪 耫 耬 耭 耮 耯 耰 耱 耲 耳 耴 耵 耶 耷 耸 耹 耺 耻 耼 耽 耾 耿. From the context I think the only sensible one is 考.e3 81 ??: This is the last hiragana in a sentence that seems to be a question, so I guess this is か.e3 ?? ??: From the context, I guess these hiraganas are の and は. The second hiragana cannot be を, as it would have been represented by e3 82 92, and 8292 is a valid character in Shift-JIS (a full-width lower case r), so it can’t have been converted to a question mark.
Which gives:
e3 81 93 こ e3 82 8c れ e4 bb a5 以 e5 a4 96 外 e3 81 ae の e7 b6 b4 綴 e3 82 8a り e3 81 af は e8 80 83 考 e3 81 88 え e3 82 89 ら e3 82 8c れ e3 82 8b る e3 81 a0 だ e3 82 8d ろ e3 81 86 う e3 81 8b か
There we have it:
My otherwise entirely unfounded guess for the hover text as a whole (blue = unsure):
神聖なるメッセージによると秘封俱楽部（これ以外の綴りは考えられるだろうか？）は複数名で構成される。
ノイズ■ブレーションと■の影響予測計算から推測され■空■からも、複数の宇宙の存在が示唆される。それぞれ、メサイアと呼称し■■■■■■■■
Melonbooks message
In the Melonbooks page of this album, in the message from the author, there is again a Mojibake paragraph:
This is converted from the album intro in RD’s own page:
Melonbooks has formatted the Mojibake (e.g. converting half-width characters into full-width), so the message from its page cannot be inverted.