I Want to Love You Till Your Dying Day manga volume 1 features story and art by Nachi Aono.

Death lurks behind a mysterious orphanage where children train to become magical weapons of war. Among them is Sheena, who longs to stop the fighting and end the conflict. On one gruesome night, Sheena meets a strange girl covered in blood, with a smile on her face. The mysterious girl turns out to be a secret weapon—an immortal child soldier named Mimi. When the two become roommates, there is growing tension and attraction. How will the peace-loving Sheena live with someone who welcomes death?

I Want to Love You Till Your Dying Day manga volume 2 features story and art by Nachi Aono.

Undeterred by war and violence, Sheena commits to protecting Mimi, an immortal girl deployed into battle. As the two become closer, Mimi puts national security at risk when she discloses her status as a classified military weapon. This lapse in judgment angers the authorities, including those who run the magical orphanage. Mimi throws herself into even more deadly clashes and survives fatal wounds—thanks to a dark magic connected to love. Can Sheena harness that power to rescue Mimi and help bring about peace?

I Want to Love You Till Your Dying Day manga volume 3 features story and art by Nachi Aono.

Prayers are Sheena's only source of hope and comfort as she watches Mimi head into combat night after night in a senseless war. While the immortal Mimi continues to thrive in battle, the teachers at the orphanage decide it's time for others to sacrifice their lives. The chosen one is the stoic and gallant Seiran who is ready to fight in order to protect the girl she loves. As the war targets more vulnerable victims, will the injustice finally force Sheena to reconsider her love for Mimi?