Soul Mates at Heart in Chinese / Japanese...

心の伴侶 is a Japanese-only title for soulmates.

心 means heart, soul, mind, core, or center. In ancient times, the heart was believed to be the mind or center of your soul and being.

の is a possessive article that connects everything here.

伴侶 means mates, companions, partners, and spouses.

This Japanese version of soulmates is about two partners, coupled or joined by their hearts.