Oshiro found out about her breast cancer when a mammogram revealed a large, walnut-sized tumor. After more testing, Oshiro was diagnosed with Stage 2 Breast Cancer on Aug. 22, 2012.
"On a fluke I found out I had breast cancer," Oshiro said. "Never would have imagined it. The only reason why I got a mammogram was my foot was hurting so I went to get an X-ray of my foot and when I was at the place I said, 'Oh I'm 40 should I get one?' That's the only reason I got it, so tell women to get checked."
The La Mirada native attended an Angels game the night before her first round of chemotherapy. Oshiro is now done with chemotherapy and had her surgery five weeks ago.
Throughout chemotherapy, Oshiro, who has been an Angels fan "since before they were popular," became a huge fan of Mike Trout.
"There are things you have to focus on when you are going through chemo and Mike is one of the things I focused on."
During Monday's batting practice, Oshiro had a chance to meet Trout and took a photo with him while he signed her ticket and a bat.
As the Honorary Bat Girl, Oshiro was presented with a customized jersey, a certificate signed by Commissioner Bud Selig, pink MLB merchandise and four tickets to Monday's game.
The 30 Honorary Bat Girls were selected by fan votes on HonoraryBatGirl.com and a guest judging panel that featured CC Sabathia, Matt Kemp, Andrew McCutchen and Alex Gordon.
The Honorary Bat Girl program -- established in 2009 -- helps MLB raise support for the "Going to Bat Against Breast Cancer" initiative, which is celebrated annually on Mother's Day.
The advocates of the Orange County Affiliate of "Susan G. Komen for the Cure," along with survivors and breast cancer awareness advocates, also took part in the ceremony.
William Boor is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.