Happiness Battle

Dead Body displayed on the terrace of gangnam’s best apartment

The incident happens in the most expensive house in the area, 102-702, High
Prestige Apartment, located in Gangnam—the richest neighborhood in Korea.
Husband Gang Do-jun is found barely breathing with a knife stuck on his back, and
his wife Oh Yu-jin is found dead with her stomach hanging over the terrace banister.
Jang Mi-ho learns about her death, a friend from the past she’d never seen for 17
years. They were best friends in high school but grew distant after their math teacher
committed suicide. Mi-ho feels guilty about the past and starts investigating Yu-jin’s
death.

“Happiness Battle” on social media among soccer moms

Jang Mi-ho finds out that Yu-jin was engaged in a “happiness battle” on social media
with her fellow moms who send their kids to English kindergartens. She is suspicious
of Song Jeong-ah and Kim Na-young, who have been her mortal enemies. Oh Yu-jin
cleverly mocked Na-young when she found out that Na-young’s husband and the
kindergarten teacher were having an affair. Yu-jin also blacklisted Jeong-ah on the
Internet community for wealthy moms when the business of Jeong-ah’s husband
was going through a difficult time. But both claim that Yu-jin was obsessed with
the kidnapping case at the English kindergarten that happened 2 years before her
Home Thriller death, and they had merely put a “drop of suspicion” in the glass of water.

Turn of events, she stabbed her husband and killed herself?

The police officially announces that Yu-jin stabbed her husband before killing herself.
But Mi-ho is still suspicious and discovers a flash drive on her laptop while watching her previous live streaming video clips. Mi-ho breaks into Yu-jin’s house and finds out that her husband is also looking for the flash drive.
What in the earth is hidden in that drive? Jang Mi-ho learns there are unexpected secrets as she uncovers the truth and confronts Yujin’s husband Do-jun.