Anime adaptation of the manga Kuroi Ame ni Utarete by Nakazawa Keiji.

Japan, summer of 1945. Nobuko, an elementary school girl, saves a little cat from crows. She desparately wants to keep the cat in her home. It is the time everyone suffers shortage of food, so naturally her parents don't like the idea. But Nobuko manages to convince them. She names the cat Kuro (black). Kuro eventually brings laughter to the family. However, the war situation becomes worse and worse... 
(Source: sazuma.com)

Three years have passed since the bombing of Hiroshima and Gen is now a fourth-grader. Hiroshima is still a ruin, and Gen must scrounge for scrap metal to help keep himself and his remaining family fed, but at least commerce has returned to the land. As his mother gradually grows ill from radiation sickness, Gen and Ryuta befriend a group of orphans led by a tough-nosed older child and including a girl who still bears ugly burn scars from the day of the bomb. An old man suffering from depression is also drawn into the group as they come together to support each other and form a makeshift family. Reality is still harsh, however, as many orphans still die lonely deaths and the grim reminders of what happened linger everywhere.
 
(Source: Anime News Network)

It's the summer of 1945. 3 years have elapsed since the war between Japan and USA began. Gen is a young boy living a struggling yet satisfying life in the city of Hiroshima, that has been strangely spared by the bombing taken in almost every other Japanese City. Food is scarce, and Gen's family is suffering from severe malnutrition, which endangeres his pregnant mother. There isn't much spare time as Gen and his little brother Shinji help their father and mother at work and try to make sure their family survives the tought times. Little do they know, what the Americans have in store for the city of Hiroshima and as of the 6th of August 1945, their lives are about to change dramatically.
 
(Source: Anime News Network)

GEN Productions