Possible Clues:

• Man's feminine side, per Jung
• Inner feminine side, in Jungian psychology
• Jung's yin
• Jungian feminine side
• Male’s unconscious feminine side, to Jung
• "Jung at heart" persona?
• True inner self, in Jungian psychology
• Inner personality
• Jung's 'inner self' — mania (anag)
• Psych term that anagrams to "mania"