While Kyotaro and Yamada are the focus, Sakurai seeds several other relationships:
A unique element of these relationships is "Parallel Shifting." Characters often grapple with the knowledge that the person standing in front of them might have briefly swapped with a version of themselves from another world. This creates a haunting romantic tension: Boku ni Sexfriend ga Dekita Riyuu -ep.1-2 of 4-...
You were born for this moment. And that, in the chaotic mess of modern dating, is the most romantic idea of all. While Kyotaro and Yamada are the focus, Sakurai