SHURIKENTALE: Shinobi Of The Worlds

From a family of skilled shinobi, Kein is forced to learn the art of assassination, despite not wanting to. To making him a strong fighter to literally torturing him to endure the pain, he feels alone and afraid of the outcomes.
Luckily, his best friend Nyoko is there to support him. A girl in which has been suffering as much as him with her own problems.
In the times of the great war, these two friends must adapt to the new lifestyle and finally find true peace.
But who knows how the tables will turn with the faith of their world...