I temporarily moved in with my older brother and his wife while job hunting. One day, my sister-in-law, Yuri, asked me to show her a collection my brother had been gathering as a hobby, so she entrusted me with the key to his study. On the computer in the study, I unexpectedly discovered videos saved by Yuri herself—footage of her masturbating and hidden camera recordings of her affairs. When confronted, she admitted to installing the cameras herself. Behind her actions lay shocking, unimaginable reasons.