Milwaukee received left-hander Will Smith, who spent most of the past couple seasons shuffling between Kansas City and Triple-A Omaha, and between the bullpen and the starting rotation.
Royals general manager Dayton Moore said on a conference call that he envisions Aoki batting at the top of the order, just as he did with the Brewers, which would allow Alex Gordon to slide down into an RBI-producing role. Aoki hit .286 with eight homers, 37 RBIs and 20 steals last season.
Aoki, who turns 32 next month, also ranked second in the majors with 40 infield hits, and .339 against left-handed pitching, the best average by a left-handed hitter in the big leagues. He struck out just 40 times in 674 plate appearances.
"We like his energy, we like his work ethic. He's a pro," Moore said. "We had a chance to see him a lot in Japan coming up. ... We'll see how it plays out."
Aoki, who is in the last year of his contract, is due $1.25 million this season. He can also make up to $1,087,500 in performance bonuses based on starts and games played.
The Royals already bolstered their rotation this offseason by agreeing to a four-year, $32 million deal with Jason Vargas. Now they've acquired the leadoff hitter they have long coveted.
Moore said he's still working on adding an impact bat, especially in the outfield. Veteran outfielder Carlos Beltran, who began his career with the Royals, spent time in Kansas City earlier this week. He's reportedly seeking a three-year, $48 million deal.
"They're far and few," Moore said. "That being said, that's an area we're trying to pursue, but let me say this, we definitely feel all our offensive players are still improving. They have not reached their peak performance. They're going to continue to get better."
By moving Aoki, the Brewers could head into next season with rookie Khris Davis in left field, Gold Glove-winner Carlos Gomez in center and Braun in right. Braun is expected back after his season-ending, 65-game suspension for violating Major League Baseball's anti-drug agreement. Davis emerged down the stretch last season, filling in for Braun in left by hitting .279 with 11 homers.
Brewers general manager Doug Melvin had said in late September there were discussions within the organization about whether to move Braun across the outfield.
"The thinking is it's a little easier to find left fielders than it is right fielders," Melvin said. "If you're trying to field right field with a platoon situation, then both guys have to be able to throw well. Both guys have to be good defenders."
Melvin said he's been watching Smith for a couple years. He called Smith a "24-year-old, big, physical left-hander who we feel can be part of our staff."
The Brewers finished last season with five right-handed starters, headlined by Yovani Gallardo and Kyle Lohse, and Smith gives them an option for a left-hander to slot into the rotation. He went 6-9 with a 5.32 ERA in 16 starts two years ago.
Smith went 8-10 with a 4.76 ERA in 35 games, including 17 starts, during his time in Kansas City. The Royals have a deep bullpen and Smith pitched primarily in relief, going 2-1 with a 3.24 ERA last season, which ultimately made him expendable in a trade.
Smith said Thursday that while he developed a slider to complement his fastball during relief work, "I am excited to get a shot back in the rotation."
And yes, he's preparing to hear a fresh round of jokes from his new team about sharing the same name as the famous Hollywood actor.
"I get them all the time," the easygoing Smith said in a conference call. "I think I'm just learning to live with it. ... It's all good."
The Royals' deep bullpen ultimately made Smith expendable.
"I feel like our team is improved with the signing of Jason Vargas and the trade for Nori," Moore said, "knowing full well we're going to have to continue to look for ways to improve if we're going to win a world championship. I don't view this move as us being complete."