Saikano, known in Japan as Saishū Heiki Kanojo (最終 兵器 彼女, Saishū Heiki Kanojo?, lit. "She, the Ultimate Weapon" or "My Girlfriend, the Ultimate Weapon") is a manga, anime, and OVA series by Shin Takahashi, creator of Iihito and Kimi no Kakera. Saikano was originally serialized in Shogakukan's Big Comic Spirits magazine.
A live-action movie adaptation was released in Japan on 28 January 2006 with Aki Maeda starring as Chise.
The Saikano manga and anime series has been licensed and is being distributed by VIZ Media in English in North America and the anime series is distributed in the UK by Manga Entertainment (as "She, the Ultimate Weapon").
Many of the locations used in Saikano can be found in Otaru-shi, west of Sapporo. The train station, "Hell's Hill", the Asahi Observation Hill, and the school all exist within the city.