They think this is all the proof needed.
On March 18, 2025, Garo Sero Research Institute released a video of Kim Sae Ron and who they claim to be Kim Soo Hyun at her house. The background seemed to match that of her known home interior that she has showcased before on variety shows.
The video shocked many and seemed to serve as confirmation that the two were indeed dating. Although Kim Soo Hyun’s face was not revealed in it, many netizens could recognize his voice and hand.
What caught the eye (or ear!) of many was the show being played in the background. Netizens deduced that the show in the background of the video was either Journey To The West or Knowing Bros.

What’s more is that BLACKPINK Jennie‘s “Solo” is being played in the back. Her song was released in 2018.

If the video was taken in 2018 as Garo Sero Research Institute claims, and as the BGM indicates, Kim Sae Ron would only have been 19-years-old, making her a minor at the time he allegedly visited her house.
You can watch the video below.