In 2024, Japanese inventor ZAWAWORKS—also known as student Yūki Aizawa—introduced a curious prototype: a bra that could only be unlocked by the fingerprint of the wearer’s partner.

The clasp contained a tiny biometric sensor, programmed to recognize just one fingerprint. Once registered, no other touch could open it. The idea quickly spread across social media, drawing equal parts laughter, intrigue, and debate.

But as Knowledia later reported, the bra was never intended for the market. Aizawa described it as a “fantasy invention”—one of many playful gadgets designed to spark conversation rather than sales. More than a product, it was a tongue-in-cheek exploration of intimacy, trust, and privacy in modern relationships.

Half satire, half thought experiment, the invention blurred the line between technology and romance—reminding us that even in the age of smart devices, some things are meant to be taken with a smile.