Porco Rosso (紅の豚, Kurenai no Buta?, lit. "The Crimson Pig") is a 1992 anime film by Hayao Miyazaki about an Italian World War I fighter ace, now living as a freelance bounty hunter chasing "air pirates" in the Adriatic Sea. The man has been cursed, and has the head of a pig. Once called Marco Paggot, he is now known to the world as "Porco Rosso", Italian for "Red Pig." Because he flies a red plane, there is resemblance to the "Red Baron", Baron Manfred von Richthofen, who was a famous German pilot of World War I.

http://en.wikipedia.org/wiki/Porco_Rosso

Actually Daphne you are mistaken, the background of Grave of the Fireflies is more tragic in reality, the anime is an adaptation of the semi-autobiographical novel of the same name by Akiyuki Nosaka, intended as a personal apology to the author's own sister. And was written and directed by Isao Takahata for Studio Ghilbi. Hayao Miyazaki wasn't directly involved in this, something I could clearly make out as he would never make a story that's this tragic.

Hayao Miyazaki is the Hans Christian Anderson of the animated medium. When I first discovered his films, not only was I blown away by their plot lines and quality but the sheer number of them... Nausicaä of the Valley of the Wind, Castle in the Sky, My Neighbor Totoro, Kiki's Delivery Service, Porco Rosso, Princess Mononoke, Spirited Away, Howl's Moving Castle...

If you liked Grave of the Fireflies I would highly reccomend, Pom Poko by Isao Takahata.

By the way I watched Grave of the Fireflies only once in my life. But it's effect was so deep that I cannot bear to watch it again anytime soon.