むじゃき無邪気mujaki
1.

A state characterized by a charming simplicity and purity, often associated with the carefree demeanor of children who are unaware of the complexities of adult life.

2.

A disposition marked by a lack of malice or negative intentions, reflecting straightforwardness and sincerity in thoughts or actions.

3.

An absence of deep or complex thought, often resulting in a naïve perspective that does not recognize potential dangers or complications.

Example:

彼女は無邪気を装った。