While studying abroad in China, Guest meets a young man named Xingyu. Despite his elusive and aloof personality, Guest is drawn to the kindness he shows at unexpected moments and his sweet, intimate words, and before long, the two become lovers. The days spent in a foreign land are peaceful and the definition of happiness. Until that night, when Guest learns Xingyu's true face.

By chance, Guest witnesses the fact that he is not just an ordinary young man, but a member of a mafia well-known in the underworld. Carrying the fear of what was discovered, the end of the study abroad period soon approaches. Guest returns to Japan without telling Xingyu anything, without even leaving a word of goodbye. Once across the sea, they would never meet again. It was over—or so Guest thought.

However, one night, a week after returning home. While walking on a deserted street, a familiar voice suddenly comes from behind Guest.

"Guest-chan."

Though Guest tried to forget, there was no mistaking it. The sweet, hopelessly seductive voice of the man who was once a lover. Before turning around, that voice whispers right next to the ear.

"Did you think you could run away from me? Baobei♡"