カゲロウデイズ (Kagerou Daze)

Background
Jin's third work and one of the tracks for the Kagerou Project. It is his most notable song; the original Nico Nico upload has over four million views.

The story behind the song revolves around a boy, Hibiya, and a girl, Hiyori. On August 15, Hibiya witnesses Hiyori running out into the street to retrieve a black cat and getting hit by a truck. The heat apparently mocks him in his daze, and he blacks out. He wakes up and it is August 14. He tells Hiyori about his strange dream that took place in the park they were walking in. Just as she steps in front of him, a pole falls from the sky and pierces through her. The heat once again laughs at him, and, before he blacks out, he notices Hiyori seems to be smiling as she dies. This process repeats for decades, the same two days happening again and again. Finally, Hibiya decides to take action and pushes Hiyori out of the way of the truck and is killed himself. In the end, it shows Hiyori was also caught in the loop. It turns out that she had been trying to save Hibiya from death, so the cycle still continues on.

This song is featured on Jin's albums MEKAKUCITY V'S, Mekakucity Actors, and Mekaku City Days. It is also featured on the compilation albums EXIT TUNES PRESENTS Vocalodream feat. 初音ミク, HATSUNE ROCK feat.初音ミク, VOCAROCK collection 3 feat. 初音ミク, VOCALOID 超BEST -impacts-, Hatsune Miku 5th Anniversary Best ～memories～, Hatsune Miku 5th Anniversary Best ～impacts～, and VOCA NICO☆PARTY.

Concerts
This song was featured in the Hatsune Miku Magical Mirai 2014 concert.

Sheet Music
Piano sheet music appeared in the Piano Solo Yasashiku Hikeru Vocaloid Selection for Piano 2 collection. This song has also appeared as sheet music in the Vocaloid Best Selection series and in Vocaloid Super Selection.

Mook
It is also featured in the magazine/book Vocalo☆Band Score vol.2.

Novel
The first volume of a novel based on this song was released on June 11, 2012 from KCB Bunko. The sixth volume was released on April 10, 2015.