PART 1: THE SHAREHOUSE, SONIC AND KIM NAMJOON 

Why everyone at the beach was frustrated that Namjoon was there too? And why was that Sunhee tried her best to avoid him? How close was Sunhee to Yoongi, Jin, Jimin, Taehyung, Taehee and Yohee that she had found refuge when she ran from Seunghyun? And how the hell did Sunhee obtained her café, the Sonic? (Read or reread After The Vow so you can understand me here)

This will be the answer.