Tsukuyomi or Tsukiyomi (月読の命 or 月夜見の尊, Tsukuyomi-no-mikoto), also known as Tsukuyomi-no-kami, is the god of the moon in Shinto and Japanese mythology. The name Tsukuyomi is a combination of the Japanese words for "moon; month" (tsuki) and "to read; to count" (yomu). Another interpretation is that his name is a combination of "moonlit night" (Tsukiyo) and a verb meaning "to look at" (miru). Yet another interpretation is that the kanji for "bow" (弓, yumi) was corrupted with the kanji for "yomi". "Yomi" also may refer to the Japanese underworld, though this interpretation is unlikely.
Tsukuyomi was the second of the "three noble children" born when Izanagi, the god who created the first land, Onogoro-shima, was cleansing himself of his sins while bathing himself after escaping the underworld and the clutches of his enraged dead wife, Izanami. Tsukuyomi was born when Izanagi washed out of his right eye. However, in an alternate story, Tsukuyomi was born from a mirror made of white copper in Izanagi's right hand.
Tsukuyomi angered Amaterasu when he killed Uke Mochi, the goddess of food. Amaterasu once sent Tsukuyomi to represent her at a feast presented by Uke Mochi. The goddess made the food by turning to the ocean and spitting out a fish, then facing the forest and game came out of her mouth, and finally turned to a rice paddy and coughed up a bowl of rice. Tsukuyomi was utterly disgusted by the fact that, although it looked exquisite, the meal was made in a disgusting manner, and so he killed her.
Soon, Amaterasu learned what happened and she was so angry that she refused to ever look at Tsukuyomi again, forever moving to another part of the sky. This is the reason that day and night are never together. In later versions of this myth, Uke Mochi is killed by Susanoo.