"Nowadays food is really mixed up," Yoshimine says. So, she offers traditional Japanese fare such as deep fried croquettes. They're big and they're cheap: a beef, veggie or curry croquette is $1.50, while the crab-filled version is just $1.75.

Another favorite is baked saba, a.k.a. mackerel.

"Even though it's good for the health, I'm surprised so many people go after that," Yoshimine says. She sells quite a bit of sushi as well, but bentos are perhaps the most popular item. For the uninitiated, it's a lunch box with a variety of items, such as teriyaki chicken paired with rice and salad.

The Seto Deli is small, but bright and cheery. There's limited indoor seating, plus a patio for outdoor dining. But there's plenty of parking, making it easy for folks who want to grab something to go. In fact, that's why Yoshimine opened the deli in the first place.

Thirty years ago, she started the Seto Restaurant, which is just across the street. Regular customers complained that sometimes they were too rushed to sit down for a meal. But they still wanted her food. She opened the deli to accommodate them.

Yoshimine is modest about her success.

"Ever since I started this place, I was so anxious. I can't believe I did it. Thirty years has just flown," she says.

Yoshimine came to the U.S. with her family 50 years ago. She went to high school in Chicago and describes the experience as "the best time I had in my life. They didn't know if I was Japanese or Chinese. At that time people were much nicer than now." Eventually, she married and her husband was transferred to Silicon Valley to work for IBM. Yoshimine got a job at Ford Aerospace in Mountain View.

Technology continues to play a big role in Yoshimine's life. Many customers come from nearby enterprises such as NASA and Synopsys, which are just minutes away. Business flourished during the tech boom, but then the bust hit.

"For two to three years, it was bad," she says. "Now it seems like it's coming back again, but not like before."

Undaunted, Yoshimine continues to evolve her business with new ideas to attract customers. Just this past week, she hired a woman who comes in daily to bake fresh bread. That means the deli is opening three hours earlier than before.

Although running both the restaurant and deli involve working long hours, Yoshimine has no plans to retire. When friends ask about her retirement plans, she says, "I'll be in the restaurant business. My whole life has come through here."

Seto Deli, 155 East Maude Avenue in Sunnyvale, 408.735.7777. Hours are 8 a.m. to 8 p.m. Monday through Saturday and closed on Sunday.