"It was the hardest part of my life," she said. "He was everything to me. Just having him there one moment -- and him gone the next."
But instead of buckling under the weight of the adversity, Matsuoka put her best foot forward and played her senior year of athletics in Jason's honor. She experienced the best success of her high school career in bowling, basketball and softball for Kealakehe High School.
Her accolades included being named a Big Island Interscholastic Federation's (BIIF) first-team softball selection after hitting .533 and helping the Waveriders to an appearance in the BIIF Division I championship game.
"My senior year was all for him," Matsuoka said. "Every game I played for him."
Now that she's back in the RBI World Series, she's not only playing for her late brother, but her coach, too. Big Island RBI manager James Hirayama will retire from coaching softball following this week's event. This is the fourth World Series Hirayama has guided the Hilo girls to in the last six years.
Hirayama is also the primary reason for the Big Island team's existence after jump-starting the RBI softball program in Hilo about nine years ago. But this won't mark the end of his involvement with RBI. Next year, Hirayama will begin coaching Hilo's junior boys team, including his 13-year-old son, Jamieson.
"It's a tough decision," Hirayama said. "But at the same time, it's my son's time. It's kind of bittersweet. I'm going to start coaching my son, but at the same time, I'm really going to miss the girls and the type of emotion and the type of energy they bring to the game."
None bring any more passion than Matsuoka. Hirayama has seen her grow from a backup on the 2009 team, overcome the loss of her brother and transform herself into the leader of this year's team.
"Ciana definitely took that mothering role and nurturing role with all of the younger girls," Hirayama said. "Being the shoulder that they can lean on and ask questions, the little things.
"She's really, really grown up. She's such a great young woman. It's really interesting to see her grow up and how she dealt with tragedy in the last few years."
Big Island struggled in the first two days of pool play, dropping its first four games. But whether Matsuoka can lead the girls to another World Series title is irrelevant compared to what she's been through.
Matsuoka called simply qualifying for another World Series "overwhelming."
"I was so happy," she said of her team's West Regional title victory, which clinched its spot in the World Series. "I started crying tears of joy knowing I can have another game playing softball, because this is my last year playing softball ever. Being able to bring my team and my coach here again was amazing."
The Dominican Republic and Harrisburg continue to steamroll through round-robin play in the softball portion of the 2012 Reviving Baseball in Inner Cities World Series.
Both squads stand as the only 4-0 teams and at the top of their respective divisions after two days of play.
Harrisburg grabbed 9-0 and 2-1 wins over Big Island and Hoboken on Wednesday. The Dominican Republic followed a 4-2 win over Houston with a dominant 15-0 victory over Mathews-Dickey Boys & Girls Club RBI (St. Louis) in only four innings.
Pacing the Dominicans' high-powered offense has been Elizabeth Vicioso Alcantara. Alcantara is hitting .500 with two home runs and seven RBIs in four games, boasting a monster 1.615 OPS.
Cleveland and Atlanta both hold 3-1 records and sit in second place in the American League Central and National League Central divisions, respectively. Hoboken and Houston both occupy third place in their divisions with 1-3 records, while Big Island and Mathews-Dickey Boys & Girls Club enter Thursday's final set of round-robin games seeking their first victories.