(最終兵器彼女, Saishū Heiki Kanojo), also known as She, the Ultimate Weapon, is a Japanese manga series written and illustrated by Shin Takahashi.

It was serialized in Shogakukan's seinen manga magazine Weekly Big Comic Spirits from December 1999 to October 2001, with its chapters collected in seven tankōbon volumes.

The story begins with Shuji, a high school student in a Hokkaidō coastal city, walking up to an observatory and reminiscing about his girlfriend, Chise; there he finds her exchange diaries that she purposefully left behind.

He and his friends run for cover, but notice a fast and small flying object shooting down the enemy bombers.

It was not until the OVA episodes were released that an explanation for Chise being chosen was offered: her body has the highest degree of compatibility with the weapon system.

A number of minor characters who do not necessarily know of Chise's role in the war have sub-plots that concern everyday people in the context of war: a woman whose husband is constantly away from home, a school boy who joins the army to protect his girlfriend, a girl whose civilian boyfriend is killed in a bombing, and others.

Written and illustrated by Shin Takahashi, Saikano was serialized in Shogakukan's seinen manga magazine Weekly Big Comic Spirits from December 27, 1999,[3] to October 29, 2001.

[22][23] In the United Kingdom, the series was licensed by Manga Entertainment, under the title She, the Ultimate Weapon, and released on three DVD sets from May 15 to August 21, 2006.

[28] A two-episode original video animation (OVA) side-story by Studio Fantasia,[29] titled Saikano: Another Love Song, was released on August 5 and September 21, 2005.