Song Woo-seok (Song Kang-ho) is a successful, hard working lawyer-turned-human-rights-activist in “The Attorney.” (Well Go USA Entertainment)

Two things seem obvious from watching the first few minutes of “The Attorney”: The movie is a comedy, and its protagonist is no hero.

The recent South Korean box-office hit observes the progress, beginning in 1978, of a lawyer with few credentials but much ambition. Song Woo-seok (Song Kang-ho) is snubbed by other lawyers because he passed the bar exam without attending law school, or even college. These cohorts are further scandalized when Song begins registering real-estate transactions, a task previously restricted to notaries.

His most inexcusable offense? Song makes a lot of money while doing work other attorneys thought was beneath them.

The industrious lawyer’s detractors aren’t the only ones in for a surprise; so are most of the movie’s American viewers. Midway through the story, “The Attorney” becomes a political drama. And Song rises to the occasion.

The lawyer thinks mostly of supporting his family and putting ever more distance between himself and his impoverished childhood. He’s also devoted to the modest, family-run local restaurant where he’s dined for years — and where he once skipped out on the bill when he was an impoverished student.

Song doesn’t follow politics, but he does support his friends. So when the restaurant owner’s college-age son disappears, the lawyer begins an investigation. He soon learns that Choi Jin-woo (Korean boy-band member Siwan) has been arrested and brutally tortured. His crime is being a member of a book club that reads such “seditious” literature as British historian and diplomat E.H. Carr’s “What Is History?

To the astonishment of the judge, the prosecutor and South Korea’s secret police, Song takes Choi’s case and turns a show trial into a real one. He makes public things that were formerly veiled in the name of “national security.” He divulges torture techniques, illustrated in grim flashbacks, and he takes a few body blows himself.

Fictionalized from actual events, “The Attorney” shows the transformation of a character based on the late Roh Moo-hyun, who became a human-rights advocate and later South Korea’s president. Rather than a fevered riff on national paranoia or personal vengeance, like many Korean flicks released in the United States, the movie is earnest and instructive.

“The Attorney” can be melodramatic, and first-time feature director Yang Woo-seok is not yet a singular filmmaker. But the movie is carried by its rousing pro- democracy message and a lively performance from the versatile leading man, whose credits include such notable Korean films as “The Host” and “Memories of Murder.” Song Kang-ho is well cast as an everyday champion, distinguished not by superpowers but by simple decency.

Jenkins is a freelance writer.

★ ★ ★

Unrated. At Cinemark Egyptian 24 and XD and Rave Cinemas Cintreville 12. Contains torture, political street violence and brief profanity. In Korean with subtitles. 127 minutes.