Tina Wang earned a degree in mathematics at the University of Hawaii-Manoa and was on a Ph.D. track when she decided to go a different way.

At least she can use math to add up her successes: ramen restaurants in Chicago (two), Texas (one), Atlanta (one) and now, Kapolei. More math: Her little ramen empire will more than double in 2020, with new outlets at Ala Moana and Pearlridge centers, one more in Atlanta and another in Chicago. More math: Wang founded the company just three years ago, and earned that UH degree just six years ago.

Tanaka Ramen & Izakaya opens Friday in the old Agu Ramen Bistro space in Kapolei Marketplace. It will be the first day that any Oahu restaurant has been able to offer sit-down service since late March.

But you’ve probably gathered that Wang is up for a challenge. Besides, she says, people have been cooped up for two months. “I would say they’d like to go out, have some fun, have some food.”

Tanaka Ramen is not affiliated with Tanaka Saimin on Nimitz Highway. To ease confusion, Wang added “Izakaya” to the name for use in Hawaii. Tanaka, she says, was the name of the chef who taught her about proper ramen, including making stock from pork or chicken bones simmered for eight to 10 hours.

Along with traditional ramen bowls, the menu includes gluten-free kale noodles, vegan ramen options and donburi. Prices run from $12 to $16. On the izakaya side are items like tempura Brussels sprouts, fried oysters and takoyaki, with prices starting at around $5.

Proceeds from Friday’s opening will go toward a scholarship fund for the UH math department.

TANAKA RAMEN & IZAKAYA

590 Farrington Highway

Open 11 a.m. to 10 p.m. daily

744-1231, tanakaramen.com