Wally Hogan has things going his way. He is the manager-trainer of Bullet Bradley, a fighter who has just won the lightweight championship. Life suddenly takes a not-so-happy turn, however, when Bullet gets drafted. Hogan's gangster partners "persuade him to enlist and keep an eye on the fighter, who is subsequently declared psychologically unfit for the Army. Enter Herbet Tuttle, a draftee eager to have Hogan turn him into a fighter. Hogan Reluctantly agrees only after he discovers Tuttle's aunt is the beautiful singer at a nightclub. From then on it's a case of stringing Tuttle along while trying to get close to his aunt. To further complicate Hogan's life there is a rulebook Military Police Officer who tries to squish the shenanigans.

Immediately after his boxing protegé, Bullet Bradley, wins a championship bout, trainer and ladies man Wally Hogan receives word that Bullet has been drafted. Bullet's career is controlled by mobsters Vic and Babe Breck, and when the Brecks ask Wally to enlist in order to keep an eye on the highistrung Bullet, Wally reluctantly agrees. At the Army recruiting station, Wally passes the physical and is sworn in, then learns that Bullet has been declared psychologically unfit. Realizing that the Brecks have set him up and want to be rid of him, Wally angrily vows to find another champion to beat Bullet. Later, on the train to Camp Ashton, Wally meets singer Connie Curtis, who asks Wally's by-the-book training officer, Karl Danzig, for permission to speak with one of the recruits. After Danzig refuses Connie's request, citing Army regulations, Wally uses recruit Herbert Tuttle, a diminutive would-be boxer, to distract Danzig so that he can sneak off and find her. Connie is unimpressed with Wally's flirtations, however, and reveals her hatred of boxing. Upon arriving at Camp Ashton, Danzig reports Wally and Herbert to his superior, who suggests that the wayward recruits join Danzig and become MPs. Wally at first balks at the idea, but changes his mind when he realizes that MPs have easy access to nightclubs and women. Wally and Herbert pass their MP training course, and during their first patrol, stop by the Pink Owl, a club owned by Connie. There, Wally is shocked to learn that Herbert is Connie's nephew. Connie warns Wally not to encourage Herbert's boxing ambitions, and anxious to make a good impression, Wally agrees. Danzig then catches Wally singing and dancing with Connie and orders him to dig ditches as punishment. After Wally tricks the gullible Herbert into digging for him, he is besieged by reporters, who ask him the identity of his new protegé. Before Wally can answer, Herbert pops up from the ditch and declares that he is Wally's next champion. Later, after the interview is published, Herbert is asked to fight Navy boxer Art Aragon. Although Herbert informs Danzig that Wally does not want him to fight because of Connie, Danzig insists that the match go on. During the bout, which takes place on Aragon's battleship, Wally is overcome with seasickness and cannot guide the neophyte Herbert. Herbert quickly loses the fight, on which heavy bets were made, and at the Pink Owl, Connie hears a soldier accuse Herbert of taking a dive and instigates a brawl. Wally breaks up the melee, then is ordered by Danzig to post an "off limits" sign on the Pink Owl. Not wanting to hurt Connie, who is angry at him for encouraging Herbert's boxing, Wally instead goes AWOL. Wally hides out at a boxing arena, where one of Danzig's men is scheduled to fight, and contacts Herbert, who calls Connie and tells her why Wally went AWOL. While protecting Wally, Herbert then accidentally knocks out Danzig's fighter and decides to go on for him, despite the boos of the crowd. Connie rushes to the arena and begs Wally to stop the bout, but he compulsively yells instructions to Herbert on how to win. After Herbert knocks out his opponent, Danzig finally catches Wally and punishes him with KP duty. Wally then is allowed to train Herbert in earnest, and Wally and the featherweight soon earn the right to fight Bullet and are blessed by Connie. The Brecks realize that Wally will be able to anticipate Bullet's moves, so they follow him as he drives Herbert and Danzig to a meeting, then intimidate him in front of Connie. Urged by Connie to stand up to the thugs, Wally wrecks what he believes is the Brecks's sedan, only to find out later that he has destroyed a general's car. Wally is jailed, but tricks his way out and arrives with Connie at the boxing arena just as Herbert's bout with Bullet is about to start. Hunted by his fellow MPs as well as the mobsters, Wally goes to a nearby bar to communicate with Herbert using walkie-talkies. Following Wally's instructions, Herbert takes control of the bout, and after the Brecks make one last attempt at silencing him, Wally directs Herbert to deliver the knockout punch. Later, in a train compartment, the just married Wally and Connie are joined by Danzig, who tries to recall Army regulations regarding honeymoons.