After the battle inside the Ziggurat, Chizuru and Hayate are horrified to find out that their victory would have cost Koyori her life. They agree to help Tazuna and Koyori, even though they're out of the fight now.  They tell the two of them that in order not to be found in the real world, they need to come up with a name to use inside the Ziggurat when they fight.  After a bit of thought, Tazuna and Koyori's new name becomes "Single Gear".
You and I can do anything together.
نستطيع أنا وأنت فعل أي شيء معاً
Gemeinsam können
wir beide alles schaffen.
Juntos podemos lograr cualquier cosa.
Juntos podemos lograr cualquier cosa.
Toi et moi, on peut tout faire.
Io e te possiamo fare qualsiasi cosa.
Você e eu podemos fazer
 qualquer coisa juntos.