The Love Tester (ラブテスター) is a novelty toy made by Nintendo in 1969. Designed "for young ladies and men", the device purports to determine how much two people love each other. To operate the device, both users grab one of the connected spherical metal sensors with one hand and hold each other's hands with the other; the meter on the device displays their "love score" on a scale between 1 and 100.[1]
The Love Tester was designed by Gunpei Yokoi (eventual creator of the Game & Watch series and the original Game Boy[2]), who said that he "loved explaining that the meter gave better results when people kissed the girl". It was the first product by Nintendo to use real electronic components.[1] It was also one of the few products by Nintendo during the 1960s that were sold outside Japan.[1] The device was marketed in Western markets as a "Love/Lie Detector".[2]