Okay, so this game is a little complicated. You can either watch the YouTube video I was inspired to make this from, or hopefully the explanation I provide will suffice.
The game is to connect two seemingly non related things together by using the MDL site. For example: Create a trail from Haechi to Choi Woo Shik.
This will look something like this:
Haechi-->Stars Go Ara-->Who Co Starred with Park Seo Joon (Hwarang)-->Who Starred in Fight for My Way-->Which also starred Choi Woo Shik
Each person will leave two unrelated things for the next person to make a trail for. The connection can be made between anything, you can try for the tougher version and create connections from different countries too.
I hope this made sense. So for the person who's willing to give this a try:
Create a trail from Boys Over Flowers to Kim Soo Hyun