Okajima, contrary to some early misinformed speculation, did not come to Boston to be Matsuzaka's companion. In fact, the two did not even know each other until they became teammates this spring.
The Red Sox signed Okajima as a free agent for the sole reason that they felt he could be a key player in their bullpen.
And with the exception of one pitch -- his first in the Major Leagues which was promptly deposited over the wall by Royals catcher John Buck -- Okajima has been just that.
Since that Opening Day indignity, Okajima -- who has an ERA of 0.71 -- has not been touched. He brings a string of 11 consecutive scoreless outings into Tuesday night's game against the A's at Fenway Park.
Perhaps Okajima has Buck to thank for all the success that has come his way over the last few weeks.
"When I gave up the home run to him, I thought, 'Wow, Major League batters are really great.' Because of that one pitch, now I've been able to get this far," said Okajima. "That pitch was a good chance for me to learn what I need to do to have success in the Major Leagues. It made me rethink what way I can pitch in the United States and be successful. The result of that is where I am and how I'm pitching."
Born on Dec. 25, 1975, the 31-year-old Okajima has been a Christmas present of sorts for the Red Sox. Backed by a sneaky fastball, a plus-curveball and a changeup that has become a bigger weapon than the Red Sox expected, Okajima is pitching lights-out.
"We knew he was a left-handed pitcher that had command. But we saw him more as a fastball-curveball guy based on the scouting reports and video that we watched," said pitching coach John Farrell. "The biggest surprise is how he's brought along his changeup and really a split change that's given him a pitch that's got later action and good arm speed and deception with it. To me right now, it's probably the most effective pitch of his three-pitch mix. That's not to degrade his other two. That's the one pitch that's been the most surprising."
The true coming out party for Okajima came at Fenway Park the night of April 20, when, with Papelbon unavailable, Francona brought the lefty out of the bullpen to save a game against the Yankees. Okajima went right through the meat of the Yankees' batting order for his first Major League save and was en route to folk hero status.
"He's the one guy, because of that changeup, we thought he had a chance to go through the middle of the order and that's what he had to do and he did a great job of it," said Francona. "Now, all of a sudden, Pap didn't pitch and we've got some confidence in another guy that feels good about himself. It works team-wise really well. I think we can grow from that."
"I'm willing to be a hero in the dark."
-- Hideki Okajima
In fact, Okajima has been sensational against the Yankees thus far, holding them to one hit over five innings and striking out seven.
The rivalry is intense and all, but Okajima will tell you he's seen another version of it back home as a longtime member of the Yomiuri Giants.
"In Japan, there is a traditional match between the Yomiuri Giants and the Hanshin Tigers, and from what I saw when we played against the Hanshin Tigers in Koshien, the fans were going even more crazy then the fans here at Yankee Stadium," said Okajima. "In Japan, in the grandstands, musical instruments are loud, including trumpets and other instruments. Noise is definitely louder."
The Yomiuri Giants -- the team Okajima pitched 12 of his 13 Japanese professional season for -- were every bit as prominent a team in Japan as the Red Sox or Yankees are in the Major League Baseball universe.
"My experience in Japan definitely helps me to deal with these situations, and these big games and with a lot of pressure," said Okajima.
Before he started burying changeups and curveballs by star hitters like Jason Giambi and Hideki Matsui, Okajima wasn't sure how he would fare amid his new surroundings.
"At the very beginning when I came over here, I was pretty nervous," said Okajima. "A lot of things were going through my mind. But those thoughts and concerns are all gone now. I am very glad that I came to the United States to play baseball and I'm happy to be here."
Yankees first baseman Doug Mientkiewicz went so far as to dub Okajima the Red Sox MVP for April. Okajima laughed heartily when told of that statement by his translator.
"It's still very early in the season," Okajima said. "If I heard that at the end of the season, I would be very happy to hear that. I will stay humble and I will keep working hard to continue the success."
And the more he achieves, the smaller that shadow becomes. The hero in the dark is coming to light.