Betty, una preparatissima ragazza che non riesce a trovare lavoro perché brutta, si presenta al colloquio di segretaria di presidenza alla Ecomoda, il cui presidente è Armando Mendoza...

Armando impressionato dalle capacità di Betty e non volendo assumere Patrizia, intima amica di Marcella (sua fidanzata) perché potrebbe riferirle ogni suo movimento (anche se deve sposarsi presto con Marcella, è un inguaribile dongiovanni: non vuole correre il rischio che Patrizia lo possa vedere con altre donne per poi riferirlo a Marcella...), decide di assumerla e le affida tutte le questioni più importanti; Patrizia racconta tutto ad un'inviperita Marcella...

Betty e le segretarie vedono Armando nel parcheggio baciarsi con Claudia, una modella... Armando consegna la sua agenda personale a Betty e le dice che nessuno dovrà mai leggerla. Mentre nel suo ufficio Armando si prodiga per assicurare ad una gelosissima Marcella che lei è il suo unico amore, alla reception arriva Karina (una modella) e chiede di lui...

Armando reiterates to Betty that the personal planner cannot be given to anyone. Marcela arrives at the office to complain about him leaving Patricia out of his personal affairs. While they argue about fidelity, Karina Larson, one of the models with whom he had a relationship, arrives. Betty tries to get her out of the company.

Betty tries to hide Karina's presence in Ecomoda, she makes Armando take her, but Patricia has seen her and goes and tells Marcela. They try to take Betty's agenda while Armando has left taking Karina.

Marcela asks Betty to hand over the position to Patricia, especially the diary. Armando arrives and tears up the letter and argues with Marcela. He thanks Betty for what she did and tells her that she no longer needs a probationary period because the probationary period will expire in one of these days. Mario tries to convince Armando not to get married, creating a computer program for him to find the ideal woman.

Marcela sues Armando about his womanizing past, eventually seducing him and forgiving him, promising not to interfere in his company affairs again. Román calls Betty to confirm his invitation to go out. After a discussion with his father, he gets permission. Betty waits to be picked up even though more than an hour has passed.

Betty cries inconsolably because they did it to her again, leaving her stuck. Nicolás, furious, complains to Román, who punches him. Hermes, Betty's father, arrives to complain about Román's trick on Betty, and they end up punching him.

Betty secretly prepares a project to surprise Armando and stand out at the meeting. Patricia overhears this conversation where Betty tells her mother this. Patricia is plotting something. Armando sits down with Betty to file the agenda.

Betty confronts Román and humiliates him. Patricia, assisted by Marcela, asks Betty for the reports, and Patricia hands them over as if they were hers, for which she is congratulated. Armando and Marcela doubt the need to have Betty if Patricia is capable of such an efficient job. At the headquarters, they invite Betty to lunch and tell her the company gossip.

The ugly women tell Betty the story of Ecomoda, its characters, family gossip, and Armando and Daniel's rivalries. Daniel asks the board to carefully review Armando's proposal, considering it impossible to fulfill.

At the end of the meeting, they congratulate Patricia on the report. Betty confronts her, but Marcela intervenes and convinces Betty not to tell Armando that the report was hers. The Ecomoda employees give Roberto a farewell serenade.

Armando asks Betty and Patricia to help him prepare the business plan, but Betty cleverly tells him that since Patricia wrote the report, he should do the project. She furiously agrees and asks Mario for help. Betty, in turn, asks Nicolás for help with the report.

Betty and Nicolás work on the project all night. Mario and Patricia prepare dinner and talk about love. When Patricia tries to get him to work, Mario seduces her, and they wake up in bed.

Betty spends all night doing Armando's work, but finds Armando furious because she's late. Patricia and Mario arrive late and without work. Betty doesn't get a chance to hand in the work to Armando. Hermes arrives at Ecomoda to talk to Armando.

Betty, terrified, tries to stop Hermes from fighting with Armando; meanwhile, Armando, furious, admits to Marcela that Betty is of no use to him and that he's going to fire her. Armando fires Betty without giving her the chance to hand over the work she did for him.

As they say goodbye, Betty hands him the report, and he, surprised and fascinated, hugs Betty and sits down with Mario to review it. Patricia tells Marcela about the wonderful night she spent with Mario and the possibilities she has of getting married.

Marcela and Patricia are deeply frustrated to learn that Betty wasn't fired, but that she actually created the business plan that Armando and Mario are very happy with. Mario tries to avoid Patricia.

Daniel warns Olarte that from now on he has to take care of Betty and any move she makes.

Betty becomes convinced that Armando is the love of her life after Mariana reads her letters. Armando announces to everyone that Betty will take over the financial management, taking over from Olarte. Patricia seeks an alliance with Olarte to fight Betty.

Patricia, to make Mario jealous, has Marcela set her up with his brother Daniel Valencia, which ends up being a failure due to Daniel's disdain for her. Aura María invites Betty to go out with some friends.

Betty goes out with Aura María and her friends to a nightclub, where both Betty and Aura María's friend are bored, as the man is disappointed that Betty isn't the woman he expected. Betty is terrified by Aura María's behavior with her friend.

Betty lies to her parents. Julia, her mother, is happy, convinced that Betty has met someone. Armando delegates responsibility for managing relations with the bank to Betty, overruling Olarte.

Armando thanks Betty for everything she's done for him, and she takes it as a declaration of love. A few months pass. Betty interrupts a racetrack at the club to get Armando to sign a promissory note for the disbursement of a loan. Marcela is shocked to see that Armando doesn't scold her but instead congratulates her for what she did.

Despite Marcela's fury, Armando asks Betty to stay and join them for lunch with the executives of RAG-TELA, a textile company, and once again Betty saves the business. Armando appoints her Assistant to the President. Betty cries with emotion.

Betty tells her friends that Armando named her presidential assistant, and they go to the bathroom to celebrate, but are interrupted by Patricia, who attacks them. They defend themselves, and Patricia tells Marcela. Marcela goes in to tell Armando what happened.

Marcela calls the headquarters and Gutiérrez, the chief of staff, together to inform them that they will be reprimanded and their salaries docked for assault. Armando, having heard Betty's version of events, interrupts the meeting and accuses Patricia, also announcing Betty's appointment as assistant to the president. Betty alarms Armando with the report.

Armando, in light of the situation and Betty's assessment of the goals set for Armando's project, asks Betty to tweak the data to present at the meeting. Daniel shows up at Ecomoda and asks Olarte to try to review the report before the meeting.

Mario seduces Patricia and convinces her to go out with him that night. Armando arrives an hour late at the house where his parents have just arrived from London; Marcela doesn't speak to him. Betty works on the report with Nicolás and tells her parents they're going to raise her salary. Olarte goes into Betty's office and turns on the computer.

Olarte can't access Betty's computer. Betty and Nicolás work all night on the report. Olarte and Patricia plan to distract Betty so she can't finish her work for the meeting.

Patricia manages to lock Betty's computer. Armando tells the board they have to wait for the computer to be fixed. The technician asks Betty for the password so he can access the information.

The technician accuses Betty in front of the board of having damaged the computer; she gives the technician the keys to extract the information. Betty's friends help her, and Aura María calls a friend who is a computer specialist and tells Betty that the damage can be fixed in an hour.

Betty tells Armando that the computer problem has a quick fix. He confronts the technician, who promises to deliver it in 15 minutes. The ugly women keep an eye on him. Finally, Armando announces that the report is ready and the meeting doesn't need to be postponed.

Betty presents the report to the board, while the headquarters distracts the technician and they find the report from the files he is taking from Olarte.

The ugly group gives Betty the copies of the files the technician hid, and she in turn gives them to Armando. He interrogates her and she confesses what happened, but only names Olarte as the sole culprit, saving Patricia. Armando interrogates Olarte.

Orlando removes Olarte from Ecomoda, but he doesn't betray Daniel or Patricia. Armando gathers the family together, informs them of the dismissals and the reasons for their dismissal, and in the process reassures Betty. The ugly women suspect Patricia, just as Armando and Mario do.

Betty insists that to meet Armando's goals, the costs of quality fabrics must be significantly reduced. Sofia causes a scandal with her husband by not bringing him all the money. Armando asks Betty to accompany him to do the fabric business that night.

The ugly women's headquarters dresses and applies makeup to Betty, who is to accompany Armando to a cocktail party for a business deal and fabric contract. Daniel invites Patricia to his apartment and asks her, in exchange for her silence, to spy on Betty and Armando's movements.

While Betty reviews the contract with RAG-TELA, Armando flirts with a former queen who is at the cocktail party.

Armando has to interrupt his flirtation with Claudia when a call from Marcela comes in. Armando picks up Betty on the street and takes her home, again asking her to always stay by his side and trust him.

Hermes is told that the company he works for is going bankrupt and they're going to lay off all the employees. Miguel calls Betty to reconfirm the appointment. Armando goes with Betty to the banks to register the signature.

Betty asks Armando for a job for Nicolás. Armando tells Hugo and Marcela that when he goes on his trip, Betty will remain in charge of the company.

Despite having rejected Miguel's offer, Betty recommends that Armando buy supplies from them, as their prices are the most favorable. Daniel visits Patricia to obtain information about the company.

Daniel asks Olarte to help him investigate whether the fabric dealers offered Betty commissions. Nicolás advises Betty to accept Miguel's offer. Mario goes out with Aura Maria.

Olarte confirms Daniel's suspicions about RAG-TELA. Armando, Mario, and Betty leave for RAG-TELA to sign the contract.

Armando and Mario sign the contract with RAG-TELA. Miguel calls Betty to ask how she wants their commission paid. Olarte calls Miguel, who tells him everything went very well with Betty. Daniel records this conversation.

Betty goes out to lunch with her friends and imagines what she would do with the commission she was offered at RAG-TELA. Marcela is at the club with Hugo Lombardi and Patricia when she receives a call from her brother Daniel. Betty dreams about what Armando would say if she had a lot of money.

Betty talks with Armando and Marcela about the commission she was offered. Daniel shows the recording he made to Olarte, referring to Betty's commission. Armando argues with Daniel, telling him to leave him alone. Betty says she's going to resign, but Armando doesn't let her. He tells her she's an exceptional woman, so much so that he tells Mario he plans to make Betty the owner of the new company.

Armando raises Betty's salary and calls RAG-TELA to uncover the mess he's been having with her, also demanding a 5% discount. Catalina Ángel, who will handle public relations for the new collection, arrives at Ecomoda. Mario and Armando propose that Betty design the new company, which will have only one owner: her.

Armando explains to Betty (hiding the truth a bit) the conditions and reasons why he needs to create this company. She accepts and also tells him to use Olarte's office, but she asks him not to separate her from him. Betty tells Nicolás, and he, very happy, asks if he can do interventions.