Cutting Off

My red string is connected to yours. A confession received from a peculiar childhood friend. And so, Seung-Hyun and Dong-Hwa begin dating. While in the middle of a normal date, plain old Dong-Hwa gains the ability to see the red string, and notices that Seung-Hyun's red string is going off in some other direction...!

(Source: Mr. Blue, translated)