It's an incredible film, so of course you're looking for more anime like Grave of the Fireflies. There are plenty of Studio Ghibli movies that portray happy, light storylines full of hope, with some room for emotional theatrics. Grave of the Fireflies is certainly one of the most serious films this studio has ever produced, giving us a look at the lives of Japanese citizens after the the bombings of WWII. Despite the dark nature of this film, it actually holds one of the most beautiful messages as brother and sister Seita and Setsuko show just how resilient and hopeful the power of youth can be.
Finding good Grave of the Fireflies recommendations is a relatively tall order, but we've found a few that are certainly worthy of recognition. In This Corner of the World shows a similar story about how the bombing of Hiroshima effected the lives of everyday citizens. Following the housewife Suzu and her persistence to carry on no matter what happens, viewers will find a the optimism both inspiring and heartbreaking in equal measure. Who's left behind? is also a war-time story based on the real life experiences of the creator, Kayoko Ebina, during World War II. Watching a young girl grow up and seeing how war has effected her life is always something hard to watch, but if you loved Grave of the Fireflies, it's an excellent story you should watch.
There are quite a few anime series and movies like Grave of Fireflies that you should add to your watch list. Plenty of them will make you cry, but the stories are far too important to ignore.