Long story short, Yoongi and Jimin were mermans. They were friends, usually hanging out and spying on the sailors who sail past them with big ships. They've started to often see and follow one same ship, that had four sailors : Namjoon, Jungkook, Taehyung and Seokjin.

"Aish, it's them again" Yoongi mumbles and peeks above the water surface. He looks Jimin who was humming and smiling widely while watching the sailors. "Jimin?"