white headband; white hachimaki
A white cloth headband, often associated with determination, effort, or traditional contexts.
受験生が白鉢巻を締めて勉強している。
The exam candidate is studying with a white headband tied around his head.
Compound of 白 (しろ, 'white') and 鉢巻 (はちまき, 'headband'). The exact historical origin of the white headband as a symbol of effort is uncertain.