The first song in the series. The story is about a boy named A-ya, who found a book and plays hide and seek alone. There is a rumour that the young boy had hidden himself somewhere.
This song is based off of hide and seek alone. The way the game works is by taking a stuffed doll with limbs, and replacing the insides of the doll with rice. Afterwards a red thread is used to sew the doll back together. Salt water is placed in a chosen hiding space, and the doll is placed in a water-filled bathtub. "First one to be it is (your own name)" is said three times, then you hide in your hiding place and count to ten. You then return to the doll and stab it, and say "Next one to be it is (doll's name)" three times. After that, you hide until you wish to stop the game, where you put some salt water in your mouth, go out to look for the doll. When the doll is found, spit out the salt water over it and say "I win." three times, then pour the remaining salt water over it, burn the doll and sprinkle salt in every corner of the house. People have said they have had strange experiences playing this game, such as the TV or radio turning on by itself, etc.
The song makes lots of references to the game such as a strange news broadcast playing on the TV.
The second song in the series. This song is based on an urban legend of doppelgangers, where it is said that if you see your doppelganger, you will die within three days. In the lyrics, you can find Japanese traditional games related to shadows (kageokuri or kagefumi/shadow-stepping tag).
This story is about B-ko who sees a news broadcast about doppelgangers, but thinks that it is a "stupid story" and ignores it. Afterwards, she sees her own doppelganger and dies due to ignoring the Bookmark of Demise's demands. This song is related to Aimless Imitation Chair Stealing Game.
The third song in the series. This song is based on the urban legend, Mearry-san.
It tells about C-ta who constantly receives messages from an unknown person called @mearry1713. Throughout the song, he keeps receiving these messages and having flashbacks to the past. At one point, he kills A-ya from Lonely Hide and Seek; at the end of the song, he is sent one final message, saying, "I'm right behind you".
Sora (illust), Yuuki Iwakura (video), Saine (main design)
The fourth song in the series. This song is about D-ne who was granted the "The Monkey's Paw" by the Bookmark of Demise, which could grant three or five of its owner's wishes. The girl wishes to become B-ko from Warning of Impostors; but then dies because she did not do B-ko's demands from the Bookmark of Demise.
Wannyanpu (illust), Yuuki Iwakura (video), Saine (main design), Kara (support)
The fifth song in the series, which can be seen as an answer song to the other four songs in the project, as it contains events from all of the other songs, such as A-ya playing hide and seek alone, C-ta's murder of A-ya, D-ne's imitation of B-ko, and A-ya and C-ta's childhood.
After getting a couple words from each participent in the Demise Game, it opens upon the group play Kokkuri-san to summon the Bookmark of Demise.
In the middle of the song, the text that slides in on the television says: "Good evening, it's the occasional broadcasting, NNN From NNN occasional broadcast, we will tell you of today's sacrifice Today, the person you saw walking while carrying a phone The person who bought a rabbit because his life was lonely The person who achieves walking 10,000 steps everyday The person who talks to someone directly if something bothers him The person who has gone to play hide and seek alone Now, the pale you, Is tomorrow's sacrifice may your soul rest in peace, good night."
About Warning of Impostors
In the beginning and the end of the song, the weather forecast says: "Good morning. I report to you, today's weather forecast. Today, there are warnings of imitations in some areas. Please be careful."
Perfect Crime Love Letter and Hide and Seek of Isolation are both connected. One verse of Hide-and-Seek of Isolation says "The prologue is told ironically, As a perfect crime". Another reference is a verse of 'Perfect Crime Love Letter'that says "Your bored face when you smiled"; 'this could refer to A-ya of Hide-and-Seek of Isolation, who was bored of his everyday life.
Similarly, Warning of Imposters and Aimless Imitation Chair Stealing Game are connected.
As well, there are several other connections between the songs, mostly minor audio or visual things.
The events of Warning of Imposters and Aimless Imitation Chair Stealing Game happen at the same time, while Perfect Crime Love Letter happens during Hide and Seek of Isolation.
On an instrumental track on the Re:After School album, 150P mentioned that the series is mostly up to interpretation by the viewer.
The emblem of the school the characters attend, which can be seen on their uniforms, appears to be an open book covered with a red mark that seems to be either a question mark or a snake with two olive branches in the background.