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(fighting) spirit; motivation; effort
shout (for getting in the right mood to deal with something, etc.); cheer; yell
kiai; short shout when performing an attacking move
気合いを入れて！
Put your spirit into it!
気合いが重要だ。
Fighting spirit is important.
気合いを入れ直す必要がある。
It's necessary to regain one's spirit.