Johjima, 29, rejected a one-year offer worth $10 million US to remain in Japan with the Fukuoka Softbank Hawks.
Instead, he is projected to become the first Japanese player to catch full-time in the major leagues.
Infielder Len Sakata, a Japanese-American born in Honolulu, served as third-string catcher for the Baltimore Orioles, winning a World Series in 1983.
Kenji Johjima is all smiles Tuesday. (AP Photo/Nam Y. Huh)
"It is an honour to become a member of the Seattle Mariners," Johjima said. "They were the first team to come to me and they have pursued me with great sincerity, which meant lot to me.
Johjima batted .309 last season with 24 home runs, 57 runs batted in and 70 runs scored in 116 games before breaking his left leg on Sept. 22.
Winner of seven consecutive Gold Glove Awards, he is a .299 hitter with 211 HRs, 699 RBIs and 597 runs in 1,117 games over 11 NPB seasons, all with Fukuoka of the Japanese Pacific League.
"He swings the bat and we can use every good bat we can get," Mariners manager Mike Hargrove claimed. "I'm very excited about him joining the ballclub."
Seattle employed seven catchers last season - Dan Wilson, Pat Borders, Miguel Olivo, Wiki Gonzalez, Miguel Ojeda, Rene Rivera and Yorvit Torrealba - and they combined to produce a lowly .216 average, 10 home runs and 46 runs batted in.
"This was a unique opportunity for us," Mariners general manager Bill Bavasi stated. "We had a chance to acquire offence at a premium position and we went after it aggressively."
"We're excited to sign Kenji and believe that this signing is one more step in our transition," Bavasi continued. "As soon as he steps on the field, he makes our major-league roster better, and that's what we needed as we headed into this off-season."
Communication could be a problem, however, because Johjima speaks limited English.
"He has started his English lessons and has a strong desire to play over here," Hargrove said. "Language won't be an issue."
"I don't anticipate it taking him a long time to catch up. Kenji is a good baseball player, number one, and it has been my experience that good players know how to get people out."
"When we met with him, he made a point of using English as much as he could," Bavasi added. "That leads me to believe he will be fine.
"He is going to have to pick up English and Spanish to a limited degree and we have to have some patience with him."
Johjima won three NPB championships (1999-00, 2003) with the Hawks, who are managed by legendary slugger Sadaharu Oh.
"Even though today is one of the happiest moments of my life, I fully understand that I have a lot of work ahead of me," said Johjima. "I need to learn about my pitchers and I need to work hard to earn their trust.
"I will do everything I can to adjust to the major leagues. And I hope that I can help (Seattle) get back into the playoffs."
with files from Sports Network
