restless, agitated
彸 centers on a state of inner disturbance: being restless, agitated, or unable to stay still.
彸 combines 彳 (movement) with 公, which likely contributes the sound. The exact historical development is uncertain, but the character is associated with restless motion.
The left side 彳 suggests movement, and the right side 公 looks like a person with arms flailing. Picture someone pacing back and forth, unable to settle down.
For ショウ, imagine a restless person at a show, constantly shifting in their seat: show -> ショウ, and their agitation matches the kanji's meaning.
—