Shikiya
No one knew why this café was so particularly special. There were theories, of course: the most popular being that it was a site where ley lines intersected - the café had been aptly named the Nexus for this reason. It was a place where those with special marks on their skins came to try and meet their fated partner.
There weren't a lot of people in the world with soul marks, percentage-wise, but enough that it was an accepted part of romance culture. Not all marks had to mean romantic connections, but those were so few in number they tended to fly under the radar. Regardless, those who wished to find their soul match in a world with far too many blank skins found themselves drawn to these "nexuses." The statistic probability of meeting your match in such a place was actually quite high.
Something about the location, scientists claimed, made the soul bond more apparent. While you might miss the weak impulses elsewhere, it was pretty much impossible to ignore your match in a nexus. Hence, the popularity of the café.