Sample Code:
[Serializable]
public class Mascot
{
[SerializeField]
public string Name;
}
var mascot = new Mascot();
mascot.Name = "ユニティちゃん";
var json = JsonUtility.ToJson(mascot);
var resule = JsonUtility.FromJson<Mascot>(json); // error in this line
Error Message
ArgumentException: JSON parse error: Missing a closing quotation mark in string.