Real life

• The Japanese
  Japanese language
  is a language spoken by over 130 million people in Japan and in Japanese emigrant communities. It is a member of the Japonic language family, which has a number of proposed relationships with other languages, none of which has gained wide acceptance among historical linguists .Japanese is an...
  
   word 鼠 literally meaning "rat
  Rat
  Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
  
  " or "mouse
  Mouse
  A mouse is a small mammal belonging to the order of rodents. The best known mouse species is the common house mouse . It is also a popular pet. In some places, certain kinds of field mice are also common. This rodent is eaten by large birds such as hawks and eagles...
  
  "
• Nezumi Kozō
  Nezumi Kozo
  Nezumi Kozō is the nickname of Nakamura Jirokichi , a Japanese thief and folk hero who lived in Edo during the Edo period.-Capture and tattoo:In 1822, he was caught and tattooed, and banished from Edo...
  
   was the nickname of a thief in the 19th century
• Previous name of Yuuki Matsuda
  Yuuki Matsuda
  Yuuki Matsuda is a seiyu famous for his part in voicing K' from SNK Playmore's King of Fighters franchise. His real name is Takehiro Matsuda . He was born March 3 in Tokyo, Japan. On October 20, 1997 he changed his legal name to Nezumi Miki...
  
  

Software

• Mobile Application (Nezumi) for monitoring Heroku applications
• Now-defunct Ragnarok Online
  Ragnarok Online
  Ragnarok Online , often referred to as RO, is a massively multiplayer online role-playing game or MMORPG created by GRAVITY Co., Ltd. based on the manhwa Ragnarok by Lee Myung-jin. It was first released in South Korea on 31 August 2002 for Microsoft Windows and has since been released in many other...
  
   server emulator released under the GNU General Public License

Fiction

• Race of anthropomorphic rat creatures in the Magic: The Gathering
  Magic: The Gathering
  Magic: The Gathering , also known as Magic, is the first collectible trading card game created by mathematics professor Richard Garfield and introduced in 1993 by Wizards of the Coast. Magic continues to thrive, with approximately twelve million players as of 2011...
  
   and Legend of the Five Rings
  Legend of the Five Rings
  Legend of the Five Rings is a fictional setting created by the John Wick and published by Alderac Entertainment Group in 1995. The setting primarily involves the fictional country of Rokugan, though some additional areas and cultures have been discussed. Rokugan is based roughly on feudal Japan...
  
   trading card games

• Nezumi, a minor character in the Japanese anime One Piece
• Nezumi is the friend of Boku in a quadrology by Haruki Murakami that includes, Hear the Wind Sing, Pinball, 1973, Wild Sheep Chase, and Dance, Dance, Dance.
• Mizune, the surname of a large family of witches who all look alike and share the same animal theme of mice, appearing in Soul Eater
  Soul Eater (manga)
  is a Japanese manga written and illustrated by Atsushi Ōkubo. Set at the "Death Weapon Meister Academy," the series revolves around three teams consisting of a weapon meister and human weapon...
  
  .
• The name of a main character in No. 6 anime.