Backlace is the name of Panty's spiritual gun. Panty has the ability to transform her panties into a gun, which can be used to battle ghosts. She first referred to it by name in the first chapter of the manga.
Unlike normal guns, Backlace does not use gunpowder, nor do any of the other gun manifestations of people's undergarments that Panty transforms. Other people's manifestations of Backlace have exhibited limited ammunition. This implies Backlace may be powered by some kind of infinite energy present in Panty's panties. Backlace's form, when transformed using briefs, is affected by the size of the user's penis.
Backlace is capable of harming demons, angels, and ghosts. Backlace can also be combined with other panties, in order to form a submachine gun or sniper rifle. If not properly maintained, Backlace will jam, as seen in "High School Nudical".
- Backlace has been erroneously regarded as "Backless" in some translations.
- It's implied by Panty's comment in regards to using Brief's underwear as a weapon, "It's just a two-pump chump", that Backlace's ammo is related to the orgasms of the owner of the undergarment. Which would make sense when using regular panties since women have no real orgasm limit.