Saishuu Heiki Kanojo

The game is based on a manga and anime series of the same name. It is set in
future, during the time of World War III. The two heroes Shuuji and Chise are
a boy and a girl who live on Hokkaido, the northern island of Japan.
Gradually, they fall in love with each other, but during an assault on
Hokkaido Shuuji discovers the terrible truth: Chise is not an ordinary girl,
but the ultimate weapon Japan relies on in order to win the war. The struggle
for Chise’s humanity and their love begins…

The game is a “digital novel” which is composed of text (occasionally with
voice acting) and still anime-style images. As the story advances, Shuuji will
have to choose between various answers and actions, determining his
relationship with Chise. It is possible to experience the story the way it was
in the anime series, or create your own story. The best ending can be achieved
by proving your love to Chise and saving her from her terrible destiny, but
there are many other endings as well.