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".
We've only been in two battles though.
لكن لم نخض سوى معركتين فقط
Aber …
Aunque nosotros solo peleamos dos veces.
Aunque nosotros
solo hemos peleado dos veces.
Je dis ça, mais on n’a combattu
que deux couples de Hand Shakers…
Parlo così, però,
Só lutamos duas vezes.