change of heart; change of mind; shift in mental state
A set phrase describing a fundamental shift in one's inner feelings, outlook, or attitude, often leading to a different decision or behavior.
He had a change of heart and decided to quit his job.
心境の変化を経て、彼女は前向きになった。
After a shift in her mental state, she became more positive.
気持ちの変化 is a more general and casual phrase for a change in feelings or mood, while 心境の変化 implies a deeper, more reflective inner transformation.
心変わり often carries a nuance of fickleness or inconstancy, especially in romantic contexts, whereas 心境の変化 is neutral and suggests a reasoned or profound shift.
Compound of 心境 (しんきょう, 'mental state' or 'frame of mind') and 変化 (へんか, 'change'). The phrase is a straightforward Sino-Japanese construction.