決意

The word "決意" describes a firm, resolute decision accompanied by a strong will or a sense of commitment. It is more formal and carries more emotional weight than "決心" (kesshin). While "決心" can be used for smaller, everyday decisions (e.g., deciding to wake up early tomorrow), "決意" is typically reserved for significant life changes, long-term goals, or high-stakes situations where a level of "resolve" or "覚悟" (kakugo) is required.

In terms of register, "決意" is frequently used in written documents, formal speeches, and serious conversations. It implies a psychological state of being unwavering in one's purpose.

Commonly, it is paired with verbs like "固める" (katameru - to solidify/firm up) or "新たにする" (arata ni suru - to renew), emphasizing the process of strengthening one's internal resolve.