What if your cat was capable of turning into a charming boy? After taking time off, Sol Ah returns to school as she finds herself a place to live alone. Per her friend’s favor, Sol Ah takes in a cat named Hong Jo, and a story of the life of two housemates unfolds. However, Sol Ah is not aware that the cat, Hong Jo, has the ability to shapeshift into a human. Sol Ah’s friends start to notice weird things about Hong Jo whenever they run into his human form. Things are about to change around the peaceful single-resident complex, and Hong Jo finds it difficult just being a mere cat whenever Sol Ah is too busy with her life to pay attention to him. Will Sol Ah be able to recognize Hong Jo in his human form? Sol Ah and Hong Jo “Welcome!” you into their romance fantasy story.
Episode 1
Sol Ah has feelings for Jae Seon, but one day, Jae Seon disappeared without saying anything. It turns out Jae Seon has been dating a new rich girlfriend whom he recently broke up with, leaving him with the cat he gave her as a gift. Because of Jae Seon’s cat allergy, Sol Ah somehow ends up taking the cat home.
Episode 2
Things would’ve been detrimental if Hong Jo hadn’t been there when Sol Ah’s dad, Soo Pyung, fainted in his apartment. Sol Ah, at the hospital, finds out about Soo Pyung’s illness and also meets his fiancée for the first time. Now that Sol Ah has to move into a new house to live alone, she feels somewhat reassured that Hong Jo is by her side although she still hates cats.
Episode 3
Sol Ah moves to a new place on her own. It’ll be her first time living alone and she’s feeling mixed emotions about it. With high hopes, she arrives at her new house and is surprised. She’ll be neighbors with Jae Seon, her first love and crush.
Episode 4
Sol Ah starts drawing webtoons again at her new place. Hong Jo continues to orbit around Sol Ah living a double life. One day, Hong Jo accidentally saves Sol Ah and becomes her life-saver. Things seem to be settling down, but there's something fishy about the new house. Is there someone else living with Sol Ah and Hong Jo?
Episode 5
Sol Ah gets a call from Sil and thinks Hong Jo is Guk Bong. Doo Sik and Jae Seon come to Sol Ah’s home to give a warning to Hong Jo, but they can’t find Hong Jo anywhere. Sol Ah asks Jae Seon why he ran away, but he only says sorry to her. Meanwhile, Sol Ah uploads “Helpless Beodul Love” Episode 1.
Episode 6
Doo Sik gives Sonamu’s free coupon to Ji Eun, and Ji Eun goes to Sonamu. Doo Sik brings Hye Yeon and Da Som to Sonamu, and they encounter Ji Eun there. Sol Ah and Doo Sik realize that Ji Eun was also a member of the art club. Meanwhile, Sol Ah tells Jae Seon to stop making her confused.
Episode 7
Sol Ah tries to move on from Jae Seon and goes on a blind date. At the meeting spot, she finds Guk Bong and realizes that Doo Sik set her up with Guk Bong. The two enjoy the afternoon anyway and come back home with fun memories. However, Jae Seon breaks the news to Sol Ah. He found someone who will take Hong Jo.
Episode 8
Sol Ah and Hong Jo both feel perplexed as Sol Ah decides to send Hong Jo off. Hong Jo feels like he’s being abandoned and Sol Ah feels like she’s letting off a good companion. Hong Jo never wished to be a human being so badly. On the day of meeting the new owner, Hong Jo disappears and Sol Ah roams around all night to look for Hong Jo.
Episode 9
Hong Jo tells Sol Ah that Hong Jo likes her. Hong Jo finds out that there was a misunderstanding between Sol Ah and Jae Seon because of him. Guk Bong comes back to his house. Sol Ah thinks Hong Jo has a girlfriend and she wants him to tell her about it. Meanwhile, Hong Jo leaves Sol Ah’s house.
Episode 10
Sol Ah thinks Hong Jo is dating Ji Eun. Jae Seon realizes that he misunderstood Sol Ah and apologizes to her, but Sol Ah doesn’t accept his apology. Sol Ah and Ji Eun become friends and have a drink together. Sol Ah encounters Guk Bong, but she still thinks Hong Jo is Guk Bong.
Episode 11
Ji Eun and Sol Ah become friends and Sol Ah gets to know Ji Eun’s true feelings about Doo Sik. Doo Sik who is oblivious about Ji Eun’s interest in him and thinks she’s the only one who hates him at work. It provokes him and he tries to persuade Ji Eun to like him.
Episode 12
Jae Seon finds out that Guk Bong is actually a cat. He’s Hong Jo. Hong Jo asks Jae Seon to keep it as a secret from Sol Ah because he wants to be by her side. In return for keeping his promise, Hong Jo begins working as a part-timer at Jae Seon’s café.