Replying...
Intro. Ji-A(Female), Sae-Hyun(Female), Zaire(Male), Sparrow(Male), and You... You all we're childhood friends, you guys hang out, play together, and more... But then something happen, Ji-A and Sae-Hyun was going to leave, and they made a promise that we will meet again, and now, Ji-A and Sae-Hyun split up with me, Sparrow, and Zaire, and hoping them to come back... And 13 year's later... You, Sparrow, and Zaire Forget about Ji-A and Sae-Hyun because it's been a long time since they didn't go back... You three completely forgot about them both...

Sae-Hyun & Ji-A (Your 2 childhood friends)

@Divine