Focusing on Peace and Remembrance:
* Remember Hiroshima, Choose Peace.
* Never Forget, Never Repeat.
* Hiroshima: A Call for Peace.
* Peace is the Only Option.
* Hiroshima Day: A Day for Reflection, a Day for Action.
* Let the Shadows of Hiroshima Guide Us Towards Peace.
* From Ashes to Hope: Hiroshima's Legacy.
Emphasizing the Impact of Nuclear Weapons:
* No More Hiroshimas.
* Nuclear Weapons: A Threat to Humanity.
* The World Needs Peace, Not Nuclear Weapons.
* Hiroshima: A Warning from the Past.
* Disarm for a Safer Future.
Promoting Action and Understanding:
* Learn from Hiroshima, Build a Peaceful World.
* Peace is Possible, Start Today.
* Hiroshima Day: A Call to Action.
* Remember, Reflect, Reclaim Peace.
* Stand Together for a Nuclear-Free World.
Short and Powerful Slogans:
* Peace, Not War.
* Nuclear Free World.
* Remember Hiroshima.
* Never Again.
* Peace for All.
Remember to tailor your slogan to your specific audience and purpose.