Most nations follow one of two main legal systems: Common Law (in the USA, Britain, Australia etc.) and Civil Law (in France, Germany, other European countries and Japan).
In the 19th century, Japan based its Civil Code on the legal codes of France and Germany, both Civil Law systems.
Although it can be jointly owned, Civil Law systems regard property as indivisible in theory, so a transaction transfers ownership completely or not at all. It makes no distinction between beneficial, legal or equitable titles, as does Common Law.
One analogy is that Civil Law treats property ownership as a box: whoever has the box, owns it. The owner can open the box and transfer the rights inside it to others, but still owns the box.
In Common Law, property ownership is like a cake. You can keep the whole cake or divide it into slices. Each slice represents a part of the ownership of the property, as there is division of ownership, not just the transfer of rights.
