Yunha Kim wanted a colleague. The colleague wanted to keep his job. So she went to speak with his boss. In the early days of Locket, Kim was trying to persuade Paul Jang to join her startup. He liked his work and felt responsible to the people he would leave behind. Kim travelled to Charlotte, made her case, and came away with an investor: his boss. Recruiting usually produces a new name on the payroll. This attempt also produced a name on the cap table.
It is a useful opening to a career full of departures. Kim has left investment banking, left business school, and sold businesses she helped create. In the neat version, those decisions form a ladder. Up close, they look more like negotiations with an existing life. There is always something reasonable to stay for. She has repeatedly found something worth leaving for.
A good job, an awkward resignation
Entrepreneurship was hardly her childhood master plan. With professors among both her parents and grandparents, she once imagined becoming one herself. Later came the possibility of law. By the time she entered investment banking, a future in a hedge fund or private equity seemed plausible. The startup chapter arrived after the respectable career had already begun.
She had earlier made a larger geographical leap. At 14, Kim left South Korea for boarding school in the United States. She has described arriving without the English she needed for lessons or ordinary conversation. Oregon Episcopal School became home for four years. The task was immediate and unglamorous: learn enough to participate, then keep learning.
Duke followed, with studies in Economics and Chinese. The combination sits comfortably in her biography: markets on one side, language on the other. She graduated magna cum laude. New York and a job at Jefferies gave her an established route into business. They also gave her an opportunity to discover that an established route could lead somewhere she did not particularly want to go.
Her own explanation of the risk was practical. In her early twenties, she had fewer financial obligations than she might have later. The possible cost of a failed venture felt bearable. There is a modest sort of arithmetic here that gets lost in the mythology of quitting your job. An uncertain outcome can still follow a considered decision.
The empty space on the phone
Locket began with a piece of real estate that people carried in their pockets. A phone’s lock screen was something its owner encountered repeatedly, often on the way to something else. Kim saw room for content there. The early proposition included advertising and small payments to users; the company subsequently developed its personalization and content offering.
That idea involved an unusually intimate advertising surface. A billboard stands beside the road. A phone sits in your hand. Locket had to make a case that appearing in that space could be useful. The proposition therefore depended on relevance, presentation, and the willingness of users to exchange a little attention for a little money.
Tyra Banks’s Fierce Capital invested in 2013. A celebrity name makes an easy headline, but the business relationship had a more specific rationale: media knowledge and advice for a young founder. Locket’s announcement described a company working out of an apartment, with pizza and ramen providing some of the infrastructure. The catering budget was evidently less developed than the ambition.
By July 2015, the business had reached more than a million users and raised $3.2 million. Wish acquired it and announced that Kim would join as head of growth. The transaction carried her from an independent startup into a larger mobile commerce business. It also gave her the experience of seeing a product become part of someone else’s plans.
One app, many voices
Kim’s next idea had a different distribution problem. She had encountered teachers who wanted a way to bring their recorded work to an audience. Building a separate app for each person seemed a cumbersome answer. Music already offered a familiar example: listeners could find many artists through one service. Why should every teacher need a separate technological front door?
Simple Habit, founded in 2016, gathered multiple voices into one platform. Short audio sessions made the format easy to explain. The more consequential choice was architectural: build somewhere that other people could publish. Kim could work on the product while contributors brought their expertise and audiences found a choice of recordings.
She began the project while attending Stanford’s Graduate School of Business. For a time, the company and the degree ran alongside one another. Then the company demanded the larger share of her attention. She left the program to pursue it. An unfinished MBA can look like a dramatic statement on a résumé. In practice, it also means deciding what gets done on Monday.
The second venture brought a different attitude toward money. Kim initially used her savings and hired an engineer, rather than immediately making outside investment the test of whether the company was real. She wanted to establish a business she was prepared to keep building. Capital, in that account, came with obligations as well as possibilities.
“You’re also interviewing them.”
Yunha Kim, on choosing investors
The reversal is small but useful. In a fundraising meeting, the founder can feel like the only person being examined. Kim’s advice asks her to examine the partnership as well. Shared values and a willingness to stay involved matter when the meeting is over and the ordinary work resumes. Money arrives once. The relationship lasts considerably longer.
A television set is a peculiar boardroom
In 2017, Kim took Simple Habit onto Shark Tank. She asked for $600,000 for five per cent of the business. The pitch became entangled in an argument between investors, including Mark Cuban and Richard Branson. She left without a completed deal. A programme built around deciding whether to invest had produced a television episode; Kim still had a company to run.
There is a temptation to treat a founder’s most visible encounter as the explanation for everything that follows. Television encourages this. The meeting has a beginning, a confrontation, and an ending. Building a business has fewer convenient boundaries. The next hiring decision, product revision, or conversation with a contributor rarely arrives with an audience ready to applaud.
Simple Habit participated in Y Combinator’s Winter 2017 batch. In November 2018, it announced a $10 million Series A led by Foundation Capital. Kim’s announcement reported tenfold growth since graduating from the accelerator and more than $5 million in annual recurring revenue. These were company-reported figures at that moment, useful as a dated picture of a business moving beyond its early experiments.
The intended use of the investment was concrete: more people, improvements to the product, a larger content library, and more contributors. A platform needs more than an attractive analogy to Spotify. It needs recordings worth finding and a service that helps people find them. As the catalogue grows, those jobs become substantial businesses of their own.
Selling the first product to back the next
Sleep Reset came out of beta in June 2022. For a period, Kim’s company operated two products. In March 2023, Ingenio announced that it was acquiring Simple Habit. The seller would change its corporate name to Sleep Reset, Inc. A company that had spent years building its identity around one app was making room for a different focus.
The distinction between product and company matters here. Simple Habit could continue with its buyer while Kim and her team concentrated their resources elsewhere. The sale did not require pretending that the earlier work had lost its value. Its value was part of what made a transaction possible. Letting it go was a decision about where the remaining company would spend its effort.
In her account of the sale, Kim said the proceeds would support further product development and team growth. Ingenio also announced that she would join its advisory board. The arrangement made another departure less absolute than it might appear: a founder could relinquish ownership of a product and still contribute experience to its next home.
Her current title adds another change in perspective. By her June 2026 school appearance, she was identified as Sleep Reset’s founder and chairwoman, and its former CEO. The verbs in her biography keep changing: start, recruit, build, sell, advise, chair. The sequence allows more kinds of work than the familiar image of a founder permanently planted at the centre of an app.
The other boardroom
There is another institution in Kim’s working life with a different population to serve. She sits on the San Francisco SPCA’s board of directors. In 2022, she publicly invited fellow animal lovers to join a proposed private shelter tour. The invitation was direct and practical: come behind the scenes, see the work, and consider adoption.
The interest predates the board seat. In a 2018 interview, asked what she might otherwise be doing, Kim talked about helping animals. She also described valuing optimism in friends and wanting colleagues to find meaning in their work. Those details offer a wider view of someone whose public biography can otherwise become a procession of financing events.
Asked for her idea of misery, she gave a compact answer: “Failing without having learned anything.” It leaves room for experiments that do not work. It demands that something useful survive them. That seems a fair way to read a career whose continuity sits in the decisions between companies as much as in the companies themselves.
In June 2026, Kim returned to Oregon Episcopal School to deliver its commencement address. The former boarding student was now the visiting speaker. Her school’s biography placed her in San Francisco with her husband and their dog, Omo. After the acquisitions, the investors, and the changes of title, the story comes back to a place she once had to learn how to navigate. This time, she had been invited to speak.