If you liked the Chocchan's Story anime, the Anime-Planet community thinks you'd like:
With their father serving overseas in the Navy towards the end of the World War 2, Seita and his younger sister Setsuko are living as normally as they can. One day during a firebomb raid on the city their mother suffers fatal wounds and the two siblings' lives are turned upside down as they go to live with a relative. After suffering the cruel treatment of their aunt, who makes it clear that their very presence is a nuisance, Seita and Setsuko decide to leave and go to live in an abandoned bomb shelter. With no one else to rely on, Seita and Setsuko try their hardest to live from day to day. Though when food becomes ever more scarce and no one is willing to sell what little provisions they have, life for the pair is increasingly difficult. Then when Setsuko falls ill, Seita begins to realize just how fragile life is...
Chocchan's Story and Grave of the Fireflies both share a lot same but again they're two individual stories of different persons.
Both are a lot similar at same time and a lot different at same time also. Where Chocchan's story is very realistic, is Grave of the Fireflies less realistic and has supernatural elements also and is a little bit unpleasant to watch a few times.