People who post obscene images and videos of themselves on social media, commonly known as "ura-aka" (secret accounts), are those who post such images and videos. Sosuke Yamada, who has an elementary school-aged daughter, happens to come across a secret account and witnesses a video of someone who appears to be his wife engaging in sexual activity. What's more, the video was taken at the elementary school his daughter attends. Is the owner of the secret account really his wife, and who is the person he's having an affair with? A forbidden secret account suspense unfolds at the PTA!