Shikishima Ritsu was living a fulfilling high school life.
Then one day, when Ritsu heard the new song from popular idol, μ, he noticed a cry for help hidding within the song.
Ritsu tried to confirm it with his friends, but none of them would respond to his questions, and they even acted off.
The suspicious incongruities continued piling up until the new year's entrance ceremonies. Yet the new students entering the school were-
All the gears composing 
the life I had been living
كل المسنّنات التي تشكّل الحياة
التي كنت أعيشها
Alle Zahnräder, die bislang
mein Leben ganz normal bestimmten, …
Todos los engranajes de la vida
que había vivido
Todos los engranajes de la vida
que había vivido
Tous ces engrenages qui composent
le quotidien que je vivais jusque-là
Tutti gli ingranaggi che componevano la mia vita
Todas as engrenagens da
vida que eu tenho vivido
Все те шестерни, 
что составляли мою жизнь,