Seita Yokokawa (横川 清太 Yokokawa Seita) is the fourteen-year-old protagonist of Grave of the Fireflies. After he and his younger sister Setsuko lost their mother in the Kobe firebombing of World War II, their lives becomes a constant struggle for survival.
Seita has dark brown hair cut short and dark brown eyes. He wears an off white Captain's cap or school uniform cap with a black viser and a beige Kokumin-fuku jacket with a name tag, white tank top underneath and beige pants with leg wrapping on his shins and black ankle lace boots.
Seita was born in 1931, ten years before his sister, Setsuko. During the Second World War, Seita's father was fighting with the Japanese navy, leaving Seita, Setsuko, and their mother to live in Kobe. During the American invasion of Japan in 1945, Kobe was destroyed in a firebombing attack. Though Seita and Setsuko were able to evacuate from the city, their mother was mortally wounded in the attack and later died in a field hospital on the outskirts of the city. They were taken in by their only remaining family, their aunt and her family. Though she initially pities them and acts kindly towards them, Seita's relationship with her eventually sours when she begins to constantly berate them – Setsuko for crying uncontrollably in the night, and Seita for his lack of contribution to the war effort. This leads to Seita packing their things and leaving their aunt's house along with Setsuko. They settle in an abandoned bomb shelter next to a lake. Though Seita is initially able to manage living with Setsuko apart from society by selling some of their mother's clothes and spending the little money she had left them, they were not registered into the national ration distribution system, and their lifestyle eventually becomes unsustainable. Driven by hunger and desperation, Seita tries to steal food from a farm to feed Setsuko, whose health is deteriorating. The farmer catches Seita in the act and brings him to a police station, beating him along the way. The police officer takes pity on Seita and shows him kindness, but is unable to help him any further. With Setsuko's health becoming worse, Seita takes her to a doctor, who remarks that she simply needs more food, much to Seita's distress. Some days later, they are informed of Japan's surrender and their father's death at sea. Seita is able to collect compensation from the navy and finally buy food, but it comes too late for Setsuko, and she starves to death. After cremating her body, Seita becomes a homeless vagrant, and as we see at the beginning of Grave of the Fireflies, he starves to death himself on September 21, 1945.
- Kiyoshi Yokokawa (Deceased Father)
- Mrs. Yokokawa (Deceased Mother)
- Setsuko Yokokawa (Deceased Younger Sister)
- Seita's Aunt (Alive)
- Seita's Cousin (Alive)
I will never... I'll never ever leave you again. Never ever. I promise.
- —Seita to Setsuko Yokokawa (Seita's younger sister)
- The name Seita means "clear, pure, clean" (清) (sei) and "thick, big" (太) (ta).
- Seita's surname Yokokawa means "side" (横) (yoko) and "river, stream" (川) (kawa).