Kokuanten (Sanskrit:Kālarātri,Kālarātrī) was one of Tembu-shin in Buddhism. She was the younger sister of Kisshoten (Laksmi). She was said to be one of three Empresses of Enma-o (the King of Hell). She was the goddess of bringing unluckiness and misfortune in the midnight.
She was also called Kokuannyo, 黒夜天, 暗夜天, 黒夜神, another name "Kokuni" (KālakarNī, meaning of unhappiness and misfortune) and so on, and it originally means "the night of the world end" in the original language.
Though she always goes with her elder sister, Kisshoten, Kokuanten with her ugly appearance and opposite character to her elder sister was said to be a goddess who brought misfortune and unhappiness.
The twelfth article of "Nehan-gyo Sutra" (The Sutra of The Great Nirvana) shows that 'the younger sister called Kokuannyo brings people evil while the elder sister called Kudokuten brings people good luck.'
These two people always go together and never separate.'
"Kuromimi" which was another name of Kokuanten in the original language in Hindooism was personalized and identified with Durga, the empress of Shiva (the god), and was considered to be the younger sister of Yama (Enma) (the god). However, according to the descriptions '次黒夜神真言' and '此即閻羅侍后也' in the tenth article of "Dainichikyo-sho", she is considered to be Empress of Enma-o in midnight in Mikkyo (Esoteric Buddhism). Her picture can be found in Gekongobu-in, outer court of Taizokai mandala (Womb World Mandala). Her figure in the picture is flesh color and holds the stick painted person's face on the left hand.