Romance is a bonus book

On her wedding day, Kang Dan-i hides out in Cha Eun-ho’s car. After her divorce, she secretly cleans Eun-ho’s place while trying to restart her career.

Eun-ho is dismayed to see Dan-i among the job applicants, but she resolves to rediscover what she wants to do with her life and move on from the past.

Eun-ho demands to know what’s going on with Dan-i, who runs into Ji Seo-jun while looking for a room to rent and later receives a kind gesture.

Eun-ho can’t recall what he did the previous night. Dan-i stumbles across Seo-jun’s dog and agrees to have ramen with the new neighborhood friend.

Dani works hard to study marketing and make up for the lost time. Eunho is always by her side encouraging and supporting her so she finds the courage to try again. They then celebrate her first month of employment. Their new book project faces an obstacle so they work hard to fix it.

When Haeri suddenly stopped by the house, Dani waited outside and accidentally met Seojun. The meeting between Dani, Eunho, and Seojun had both men bickering and Eunho all riled up after. The company goes to volunteer in an orphanage and their trip ends with a sad surprise. The new book is finally released and the whole company is waiting for the response.

Seojun asks Dani for a dinner date after work which had Eunho very annoyed. Ji Yul's mum falls for her dating lie and tries to intimidate park hoon. Eunho is ecstatic with how the dinner ended. The company directors have a big fight yet they come together especially facing sad times. Seojun tries to get close to Dani and Eunho is getting jealous.

Seojun is trying to court Dani and his efforts give Eunho a hard time. The company receives a manuscript for a big new project that Eunho and Dani were instructed to work on. A club Night ends up wilder and with more surprises than planned. Dani starts to have strong suspensions about Eunho.

Eun-ho's reply thrusts Dan-i into a daze, as it contradicts her memory of recent events, and she muses how a dog-eared book can suddenly seem new.

Dan-i's confusion becomes worry when Eun-ho doesn't answer her texts or come home. When he doesn't appear at the office, she's at a loss for what to do.

Dan-i tries to downplay the episode with Eun-ho, but he sees their situation differently. When the book concert hits a snag, her past comes in handy.

Dan-i revels in her latest feat at work and celebrates with Eun-ho, but he's given a tough order to execute after questions about her résumé emerge.

Eun-ho faces hurdles while making job inquiries for Dan-i and realizes how impossible it is for women trying to return to the workplace after a hiatus.

An unexpected source reaches out to help Dan-i land a new job after she tenders her resignation. Dan-i learns that Eun-ho's been hiding something.

Eun-ho wants Dan-i to say he did the right thing, and tries to figure out who's behind a mysterious manuscript. But he isn't the only one investigating.

Eun-ho gets a call from Gapyeong and is urged to live his life so that he may be like a book in someone’s life. Dan-i focuses on a cherished tome.