Lovely Two
Lovely Two is a portable love tester popular among girls in the Yu-Gi-Oh! manga.
The owner inputs data including their name, birth date, blood type, which creates a special waveform. By pressing a button, while in range of another Lovely Two, it will check to see if their waveforms match. Matching wave forms will result in a ringing noise, indicating the two owners would go well together romantically.
Anzu Mazaki and Yugi Mutou tested their love compatibility twice; The first time they got no reading. The second time they tried, Dark Yugi was in control of Yugi's body and a connection was established.
