主人公
しゅじんこう · shujinkou · JLPT N1 · noun
supporter
主 — flame/lamp on top of a stand 王
Originally a pictograph of a lamp with a flame on top of its stand, representing the lord or master of the household who tended the fire. The meaning extended from 'lamp/host' to 'master, owner, main, principal'. The character 炷 (wick) preserves the original 'lamp' sense.
人 — pictograph of a standing person
人 is a pictograph showing a person viewed from the side, with two strokes representing the legs and torso of a standing human. In oracle bone script it clearly depicted a figure leaning slightly forward. The meaning has remained 'person' or 'human' throughout its history.
公 — eight 八 + private 厶
Originally an ideograph showing 八 (to divide) over 厶 (private/self), depicting the act of splitting away from selfish interest. The combination came to mean 'public' or 'fair,' the opposite of private. It later extended to senses like 'duke,' 'lord,' and 'grandfather.'