Kyugo (reigning name) is a title given to an Imperial family in Japan.
It is a title given by the Emperor when a son of an Imperial family establishes a Miyake (house of an imperial prince), becomes independent, and starts making his living. Normally it is given by the Emperor when a son of an Imperial family gets married and becomes independent, but Imperial Prince Yoshihito, the second son of the Mikasanomiya family established a Miyake unmarried and was given the title of Katsuranomiya.
The Kyugoes which currently exist.
Mikasanomiya (Although Imperial Prince Tomohito became independent and is making his living, he has no Kyugo because he is the heir to the Mikasanomiya family).
Takamadonomiya (because of the death of Imperial Prince Takamado no miya Norihito, Princess Hisako, the wife of Imperial Prince Norihito is considered to be the present head of the family).