Shinnyo is a teenage boy within a late 19th-century Japanese community, defined by his role as a Buddhist priest's son. This religious environment shapes his life's path. A pivotal event occurs when his father sells his sister into becoming a wealthy man's concubine. Witnessing her later misery and desperate plea to return home, fueled by hatred for the man and his wife, sparks deep resentment in Shinnyo when his father refuses her sanctuary. This experience shatters his faith in family and societal structures.

Shinnyo shares a close bond with Midori, a girl training to become an oiran, suggesting genuine affection. Their connection exists under the shadow of their predetermined futures within a constrained society. The forced departure of his sister plunges Shinnyo into profound depression. This despair drives his decision to abandon his community entirely. He travels to Kyoto to train as a Buddhist priest himself, ultimately embracing the path expected by his family despite his earlier conflict.

His departure signifies resignation and severs his relationships, particularly with Midori. Before leaving, he makes a poignant yet troubling promise to her: to become her first customer once she begins her work as an oiran. This statement underscores the collision of their personal feelings against their inescapable societal roles. His exit to Kyoto marks the abrupt conclusion of his adolescence.