A unique trend is arising in Japanese speed dating events where participants are only allowed to join if they share the same last name. Originating from a marriage party, or "Konkatsu," this unique criterion has become an interesting attraction for many in the dating scene. The rationalization behind the trend is rooted in the idea of familiarity; individuals sharing a surname may possess a notable connection from the start, aiding in meaningful conversation and subsequently, potential pairings.

In Japan, the concept of "imekaji" (image marrying) or marrying someone with the same last name is not entirely new. It is tied to the deep-rooted custom where traditionally women adopted their husband's family names after marriage. These dating parties with same surname requirements make potential matrimonial discussions less intimidating for participants. They playfully address the social pressures associated with the declining marriage and birth rates in Japan.

In the US or EU, there are no known mainstream dating events or practices that incorporate the same-last-name criteria. However, socializing events do employ various creative criteria to ensure compatibility like speed dating for specific age groups, hobbies, or profession, but not contingent on surnames.