What does character 1 in Love of Light and Night mean?

Xiao Yi.

Character 1 in Love of Light and Night is the male protagonist Xiao Yi, because He Yi has the same pronunciation, 11 (Xiao Yi), 66 (Lu Chen), 77 (Qi Sili), 55 (Charlie Su, Diamond means "Wang Laowu"), 00 (Xia Mingxing, because his nickname is Tangyuan).