Before Jennifer Tseng began a book reading at Bunch of Grapes Bookstore a few weeks ago, she scanned the audience and cleared her throat. “I’m still searching for the perfect one line sentence to serve to people when they inevitably ask what my book is about,” she said as she prepared to read from her new novel Mayumi and the Sea of Happiness. “So keep that in mind.”

Ms. Tseng’s recent work is certainly not one that can be easily categorized. Ms. Tseng has previously published two books of poetry, and her current book is her first novel. On Saturday, June 27, at 6 p.m. a book party will be held for her at the West Tisbury Library.

Originally inspired by Patricia Highsmith’s The Price of Salt, the story of a chance meeting that inspires a great romance, Ms. Tseng’s novel evolved and now includes comparisons to books such as Lolita and The Cement Garden.

“It’s more than just a love story,” she said. “It’s a story about a person’s relationship with their self.”

Ms. Tseng began writing Mayumi and the Sea of Happiness after she decided to postpone what she calls her “true first novel.” That novel tells the partly imagined story of her father who came to America from China.

“I put it aside when my daughter was born. I put everything in a box on the shelf.”

Her father’s death also made that book increasingly difficult to work on, and Ms. Tseng ceased to make any progress. She changed direction, originally looking to create a short four-part novella, which ultimately became the nearly 300-page book, Mayumi and the Sea of Happiness, about a 41-year-old librarian who begins an affair with a 19-year-old library patron.

The books main character, Mayumi Saito, bears a striking resemblance to its creator. Both Ms. Tseng and Mayumi are librarians with a young daughter at home who live on a small New England island. But much of this likeness, according to Ms. Tseng, is coincidental.

The character of the daughter came about from a request from Ms. Tseng’s own child who wanted a part in the book. But having a child also gave Ms. Tseng a chance to explore more deeply the character of her protagonist.

“Women are already expected to sacrifice,” said Ms. Tseng. “And when they have a child, they’re expected to sacrifice more.”

The choice to have a library as the setting was made because the library has played such a large part in her own life. Ms. Tseng’s first job on the Island was at the West Tisbury Library, where she continues to work, and it was also the place she would go to escape and read a book when she was visiting before she lived on the Vineyard.

“I was trying to salvage the experience of what it feels like to be here,” Ms. Tseng said. “The book has become like a memento for my experiences.”

But it was the novel’s central subject matter, the affair between a young man and an older woman, that most worried Ms. Tseng. She feared how it might be met in the community, given the age difference of the characters, and began asking around to gauge the reaction of Islanders. Much to her surprise, the general response was a nonchalant fascination.

“Out in the world, it happens all the time,” said Ms. Tseng. “It’s at least more commonplace.”

Ms. Tseng’s own parents were 22 years apart, possibly contributing to why the age difference did not feel so extreme to her. But the protagonist’s gender and the ensuing sexual politics are also factors that she later realized could be controversial for a wider audience. Ms. Tseng noted that typically older male protagonists are the ones who engage in a scandalous affairs with much younger women in similar novels.

“I sympathize with her,” said Ms. Tseng of her main character. “But a lot of the editors who turned it down were afraid that readers would not.”

As Ms. Tseng grappled with these issues and talked to friends on the Island, she found the process helped to keep her engaged in the work, viewing the world through the lens of her character and the novel as a whole. That constant engagement helped Ms. Tseng commit to writing the entire work in a writing room overlooking the backyard of her house, pausing when she got stuck to take a whiff of a tobacco-scented cream perfume to remind her of the smell she had concocted for the young man in her book. This concentrated focus also helped Ms. Tseng move past the heartache of her father’s passing.

“It pulled me out of my own,” she said, looking up at the window of her writing room. “It just took me out of my grief.”

On Saturday, June 27, at 6 p.m. the West Tisbury Library hosts an author reception for Jennifer Tseng. In addition to a reading and book signing, there will be bubbles, cake and speeches.