It was back in mid-December that Japanese pitcher Hisashi Iwakuma and his wife got to take in Seattle for the first time.

They looked at potential houses, scouted school possibilities for their daughter and took in Pike Place Market and the other usual tourist destinations. But it was during a lengthy dinner with Mariners general manager Jack Zduriencik at a local eatery that the 30-year-old Iwakuma truly got a sense of how much the team wanted him.

And for a pitcher who had experienced an aborted negotiation with the Oakland Athletics a year ago in his first attempt at a U.S. career, that sense of being needed is what turned the tide in Seattle's favor.

"Seattle really wanted to get me," Iwakuma said Thursday, through an interpreter, after agreeing to a one-year, $1.5 million deal, with another $3.4 million in incentive possibilities. "That was the most important thing."

It sure doesn't seem like money was the biggest factor, which Iwakuma actually said during his conference call with reporters. The deal is for far less in guaranteed money than the A's were reported to be offering over multiple seasons a year ago — after they offered a $19.1 million posting fee to negotiate with the pitcher.

Iwakuma can earn just over $3 million in incentives tied to the number of starts he makes and innings he pitches, a setup designed to reward him if he can produce the type of innings-eating, middle-rotation depth the Mariners are looking for.

Iwakuma was sidelined by shoulder problems last season and scouts have expressed concern about a loss in velocity on a fastball that used to reach 95 mph. The incentives begin at 20 starts and 100 innings and max out at 30 starts and 200 innings.

They work on a climbing scale, including a $200,000 bonus for 20 starts, another $250,000 for 22 starts, $300,000 for 25 starts, and $400,000 if he hits 30 starts.

His innings bonuses work in similar fashion, beginning at 140 innings and reaching a final bonus of $400,000 if he hits 200 innings. There are side bonuses for things like a Cy Young Award, All-Star appearance and World Series MVP, but they only amount to a few hundred thousand of the total package.

Iwakuma's fastball now ranges between 89 and 91 mph, though Zduriencik said Thursday it recently hit 93 mph. It's the pitcher's low walk rate and above-average command that the Mariners hope will transfer over well from the Japanese League, where Iwakuma went 107-69 over 226 games with Kintetsu and then Rakuten, winning an MVP award and Cy Young Award equivalent in 2008.

"I think that it serves both parties' best interests," Zduriencik said of the contract. "I know that he wants to pitch here in the United States. I know he's enjoyed his short time here in Seattle. He's very familiar with the organization. And I do think he would like to establish himself here in the States and see what happens."

Iwakuma wound up leaving his former agent after the failed Oakland negotiations. He signed on with Paul Cobbe of Sosnick-Cobbe Sports. Cobbe said Thursday night that the agency brought Iwakuma in to Tempe, Ariz., to begin working out in October and had its doctors test his shoulder to alleviate any concerns teams might have about it.

Later on, the pitcher began meeting with teams that were more seriously interested and took physicals with them. Iwakuma did his Mariners physical over a couple of days during the mid-December trip.

"We just felt like it was better to have every team have a look at him," Cobbe said.

The Mariners were satisfied with what they saw. Now, they hope a pitcher nicknamed "Kuma" (which means "the Bear" in Japanese) can slot in nicely after Felix Hernandez and Michael Pineda in a rotation that also includes Jason Vargas and likely Blake Beavan.

Zduriencik said he'll continue to look at other veteran pitchers still out there, guys like Jeff Francis and Jamie Moyer, but hopes Iwakuma fills some of the experience void he'd been looking for.

"With what we have," Zduriencik said, "we feel this will be a nice mix."

Kawasaki will join M's

Japanese shortstop Munenori Kawasaki told reporters in Japan he'll be signing with the Mariners. "I'll be going to Arizona in February to compete for a job," he said, according to an Associated Press story.

Kawasaki, 30, will sign a minor-league contract but will compete for the backup shortstop job with the Mariners. He hit .267 last season for the Softbank Hawks.

Kawasaki worked out with Ichiro in Kobe on Thursday.

Geoff Baker: 206-464-8286 or gbaker@seattletimes.com