Since the user provided Japanese keywords, I should check Japanese news sources and reports. However, I have to be careful about the reliability of the sources. There might be tabloid articles or clickbait headlines that are sensationalized.

I should start by checking if Karen KAede is a real person. Let me look her up. Yeah, she's a Japanese gravure idol and actress, born in 2004. The "father-in-law" part could be a misunderstanding or a mistranslation. Maybe it's related to a legal case or a scandal. I need to verify if there was any case involving her family members.

Another angle: Karen KAede was part of a group called "SKE48," which is a Japanese idol group. If there was a family member involved, perhaps her father-in-law was involved in some legal issue that connected back to her. Or maybe there was an incident where her father-in-law was accused of inappropriate behavior, leading to a legal case involving her.