From the Start, I Swore Brotherhood in the Peach Garden and Got Carried to Victory

“I, Liu Bei, Guan Yu, Zhang Fei, and He Yue, though of different surnames, have sworn brotherhood and will work together with one heart to aid the distressed and rescue those in danger; to serve our country above and bring peace to the common people below. We do not ask to be born on the same day, in the same month, and in the same year, only to die on the same day, in the same month, and in the same year. May Heaven and Earth bear witness to this oath. May all gods and men strike down whoever betrays it or forgets this bond!” Once the oath was made, they asked one another's ages. Liu Bei was twenty-eight, Guan Yu twenty-seven, and Zhang Fei twenty-two. He Yue alone was only twenty. So they named Xuande their elder brother, Guan Yu second, Zhang Fei third, and He Yue their youngest.”

But they had no idea that one person was never supposed to be part of the Oath of the Peach Garden, and that person had transmigrated!