NieA_7 (ニアアンダーセブン, Nia Andā Sebun), also known as NieA under 7, is a doujinshi manga series created by graphic designer Yoshitoshi Abe and later published by Kadokawa Shoten on their monthly Shōnen magazine Monthly Ace Next from October 1999 to January 2001. The manga revolves around a poor, introverted student named Mayuko Chigasaki, who lives above a Japanese bathhouse, and a freeloading, freewheeling outcast alien named NieA, who lives in Mayuko's closet.

The manga is adapted into a 13-episode anime series by Triangle Staff and aired on WOWOW from April 16 to July 19, 2000. Much of the anime's staff also worked on Serial Experiments Lain, as producer Yasuyuki Ueda suggested the team work on a lighter anime as relief from the dark, heavily psychological Serial Experiments Lain. The character Chiaki, a ufology fanatic, shares a name with Chiaki J. Konaka, the script writer for Serial Experiments Lain.