Also known as: 南光太郎, 南光太郎(BLACKSUN)
The main protagonist of Kamen Rider BLACK and its sequel RX. He appears as the titular Rider in both series.
Starting with Kamen Rider Decade and continuing onto the later crossover movies, there are two of him who are independently BLACK and RX.
The older version of him that appeared in the adult reboot BLACK SUN also falls under this tag.