Avengers' Social Club

Jeong-hye, shaken by the sudden appearance of her husband's illegitimate child, happens to see Do-hui begging on her knees at a café. At a social gathering, Mi-suk has her secret exposed to Jeong-hye, who proposes forming the "Buamdong Avengers' Social Club" so they can each take revenge in their own way.

With the help of Jeong-hye and Mi-suk, Do-hui resolves her son Hui-su's bullying issue with an unreasonable parent. After forming the club, the trio successfully carries out their first revenge against an obnoxious café customer and celebrates at Do-hui's house. Back home, Jeong-hye receives a tempting offer from Su-gyeom, her husband's son from an affair.

Su-gyeom discovers the existence of the Avengers' Social Club and asks to join, but is rejected. After learning of his biological mother Su-ji's true intentions, he assaults her group and ends up at the police station. Meanwhile, when Do-hui learns that her daughter was sexually harassed by the school principal on her first day as a substitute teacher, she starts planning a grand revenge.

Mi-suk feels uneasy about her daughter Seo-yeon spending time with Jeong-uk, who bullied Hui-su. Do-hui runs into the café customer the Avengers' Social Club got revenge on and ends up in trouble, but gets help from a passerby named Seung-woo. Meanwhile, Byeong-su secretly plots to seize Su-gyeom's family property, and someone sends photos of the club to Su-gyeom's phone.

The Avengers' Social Club begins tracking down the person who sent the photos to Su-gyeom. Caught off guard by Mi-suk's changed attitude, Yeong-pyo is embarrassed by Do-hui at a local market sports event. Meanwhile, a mystery man makes Do-hui's heart flutter. Later, as the gathering at Mi-suk's house gets into full swing, the doorbell suddenly rings.

Hui-gyeong is pushed into a corner by Sang-man's unreasonable demands. Yeong-pyo visits his daughter Seo-yeon's school for an education superintendent campaign event, only to be embarrassed by her. The Avengers' Social Club heads to a sauna to unwind, where Jeong-hye's quirky side emerges. Then, Su-ji blackmails Jeong-hye with a photo involving Byeong-su in an attempt to get money from her.

Seo-yeon sees Su-gyeom with the Avengers' Social Club and gets the wrong idea about his relationship with Mi-suk. Unaware that Mi-suk switched his herbal medicine, Yeong-pyo begins acting strangely and grows wary of her. Doubting Jeong-hye and Su-gyeom, Byeong-su sends someone to follow them. When Sang-man also starts following the group, the Avengers' Social Club slowly comes to light.

After receiving anonymous threatening letters, the Avengers' Social Club searches for the culprit. False accusations shut down Do-hui's fish shop, leading Jeong-hye and Mi-suk to search for a solution. Meanwhile, Hui-gyeong faces a crisis after the media distorts her attempt to confront Jeong-uk. As the pressure mounts, Do-hui is forced to humble herself once again for the sake of her children.

The Avengers' Social Club turns Hui-gyeong's situation into an opportunity to fight back. With Seo-yeon's help, Su-gyeom uncovers that everything was fabricated, and the club finally corners Gil-yeon and Sang-man. Meanwhile, Byeong-su has been secretly siphoning off Jeong-hye's assets. Su-gyeom proposes a deal with Jeong-yun, and Jeong-hye makes her own deal to protect him.

Even after apologizing to Hui-gyeong, Jeong-uk shows no remorse, leading Su-gyeom and Hui-su to resort to a final measure against him. Jeong-hye devises a clever plan to reclaim her building from her husband. Convinced that the Avengers' Social Club is behind Jeong-hye's sudden change, Byeong-su begins plotting to drive her and Su-gyeom apart.

Unable to endure Yeong-pyo's continued abuse, Mi-suk leaves home with Seo-yeon. After discovering the Avengers' Social Club's existence, Byeong-su attempts to send Jeong-hye and Su-gyeom abroad. Still, the members begin preparing their own revenge. To help Jeong-hye, Su-gyeom, and Mi-suk, they start searching for evidence linking Byeong-su and Yeong-pyo.

Su-gyeom meets Su-ji, who is about to leave the country, and asks her to reveal that her previous interview was fabricated by Byeong-su. As events spiral beyond his control, Byeong-su tries to win Jeong-hye back. Meanwhile, the Avengers' Social Club launches a new plan to expose Yeong-pyo's corruption, but he gets ahead of them and holds a press conference first.