Secret sword to purge all evil of attack on stick vs titan.

Stick and his adoptive sister and best friend live in district - a town jutting out of castle, the outermost wall of the three walls that protects humanity from cannibal titans, which are claimed to have killed everyone else 100 years ago.

When district and city were broken through by the titan of the great form and iron armor, the invading titan forces forced humans to retreat into Castle.

After seeing his mother being eaten by a titan and her father disappearing, Stick enlisted in the army with friends, hoping to avenge his mother.