Her work “Concentration” best represents her oeuvre. Reminiscing, she says, “At that time, my teacher advised me never to paint a face larger than its actual size. The reference photograph was of an intense surgeon's face in the middle of a surgery, wholly absorbed in his task to alleviate the patient's ailment. The image was so compelling that I felt a strong need to paint it large. To show the look of concentration, the wrinkles on the face, the skin's texture, and the impact I chose a 24x36 canvas and filled the canvas with his face.”

“The photograph came from a friend of mine. I was looking for a photograph, or a model to paint of somebody who was actually operating as I was doing the healthcare series. I was taking pictures of a friend, who was also a photographer. He sent me a number of pictures and when I saw that image, it had so much impact, and became my greatest inspiration,” says the Japanese artist. The photograph turned out to be of a well-known surgeon, Dr. Edgar Rodas. who served, among other positions, as Minister of Health of Ecuador, Vice-Rector and Professor of Surgery at the University of Cuenca, President of the Ecuadorian Surgical Society, Founding Dean of the Medical School, University of Azuay, and President of Ecuadorian Section of Amnesty International.

“I received an email from Dr. Rodas' son, Dr. Edgar Rodas Jr. He saw my painting while browsing the internet for surgeons' pictures. He recognized his father's face immediately and contacted me to know more about the image. We connected, shared stories, and I decided to donate a copy of the painting "Concentration" to him in Richmond, VA, and another one to his family, who still live in Cuenca, Ecuador,” says Matsumoto.