71: Into the Fire: Plot, Cast, Ending & Where to Watch

Kwon Sang-woo

Kwon plays Kap-jo as the film's barometer for what war does to a personality that has not yet finished forming. Early scenes lean into the actor's leading-man swagger — slouched stance, contempt-curled lip — but Kwon recalibrates as the perimeter tightens, until the same body language reads as fear pretending to be defiance. His grudging concession of authority to Jang-beom inside the school's chapel is the performance's load-bearing scene; he plays the concession as the harder of the two boys' choices.

T.O.P

T.O.P (Choi Seung-hyun), making his feature-film acting debut after fronting Big Bang, plays Jang-beom as a boy too quiet for the role of leader he is handed. The casting works because his pop-star recognisability is inverted: the boy on the recruiting roster is recognisable to the audience, and the film uses that mismatch to underline how little any of these students should be there. His shaking-hand letter to his mother, written in the third reel by oil-lamp light, gives the performance its emotional centre.

Kim Seung-woo

Kim brings a weathered procedural gravity to the ROK captain who hands the seventy-one their assignment and walks away knowing what he is leaving behind. The role is technically a supporting one, but Kim's two key scenes — the perimeter handover at the school gate, and a later radio exchange while the Nakdong front is collapsing — bookend the film's moral question about command in retreat. He plays Kang as a man who has already done this calculus before and hates himself for being good at it.

Cha Seung-won

Cha plays the North Korean major as an unromantic professional rather than a villain — a battle-hardened regimental commander who has been ordered to take Pohang and is doing the math on whether to spend his battalion's strength on a building full of children. His on-foot reconnaissance of the schoolyard, conducted in the rain in the film's second half, is a small showcase for Cha's stillness; he reads the building as a tactician rather than as a man encountering boys, which is what makes his final decision land.

Kim Hye-seong

Kim is one of the ensemble's standout younger faces, playing a quietly observant student-soldier whose letters home function as a recurring voice-over thread inside the film's three-act build. The performance is held mostly in the eyes — the scene where Yong-man helps another boy load a Garand for the first time is shot in close-up, and Kim does the work of communicating both the absurdity and the seriousness of teaching another fourteen-year-old how to fire a rifle.

Ku Sung-hwan

Ku rounds out the seventy-one's inner circle as the squad's reluctant comic-relief figure, a boy whose nervous chatter inside the schoolhouse buys the script the breathing room it needs between battle preparations. The performance avoids the obvious sentimentality the role could have absorbed; Ku plays Nam-sik as a kid who has read every adventure novel in the school library and is realising, in real time, that none of them prepared him for the actual sound of artillery.