While kaishu is often perceived as a formal and structured script, a closer examination reveals its capacity to convey a broad range of emotions. This essay will explore how calligraphers manipulate the elements of kaishu to express feelings, moods, and personal states, demonstrating that even within strict rules, the script can be highly expressive. The essay will begin by focusing on stroke weight and its impact on emotional expression. We will analyze how variations in line thickness can evoke feelings of lightness, heaviness, strength, or fragility. We will discuss how thin, delicate lines can convey a sense of elegance and refinement, while thick, bold strokes can express power and determination.