expression, noun
what one feels like doing; what one has a mind to do; being so minded
Refers to a person's inclination, intention, or mood to do something. Often used in conditional or hypothetical contexts, such as その気があれば (if you feel like it) or その気にさせる (to make someone feel like doing it).
彼はその気になれば、もっと早く終わらせられるはずだ。
If he puts his mind to it, he should be able to finish it much faster.
その気があるなら、一緒にやってみない？
If you're up for it, why don't we try it together?