Ganbaru

, also romanized as gambaru, is a ubiquitous Japanese word which roughly means to slog on tenaciously through tough times.
The word "ganbaru" is often translated to mean "doing one’s best", but in practice, it means doing more than one's best. The word emphasizes "working with perseverance" or "toughing it out".
"Ganbaru" means "to commit oneself fully to a task and to bring that task to an end". It can be translated to mean persistence, tenacity, doggedness, and hard work. The term has a unique importance in Japanese culture.
The New York Times said of Shoichi Yokoi, the Japanese holdout who surrendered in Guam in January 1972, that in Japan "even those embarrassed by his constant references to the Emperor felt a measure of admiration at his determination and "ganbaru" spirit". After the 1995 Kobe earthquake, the slogan "Gambaro Kobe" was used to encourage the people of the disaster region as they worked to rebuild their city and their lives. After the 2011 Tōhoku earthquake and tsunami, "gambaru" was one of the most commonly heard expressions.
Analysis.
"Gambaru" focuses attention on the importance of finishing a task and never stopping until a goal is achieved. The continuing effort to overcome obstacles (even if not successful) is an important concept in Japan.
Unlike the related, but passive gaman, "ganbaru" is an active process.
Although there are many near synonyms in Japanese, there are few antonyms.