We determine exactly the short-distance effective potential between two “guest” charges immersed in a two-dimensional two-component charge-asymmetric plasma composed of positively (q1=+1) and negatively (q2=−1/2) charged point particles. The result is valid over the whole regime of stability, where the Coulombic coupling (dimensionless inverse temperature) β<4. At high Coulombic coupling β>2, this model features like-charge attraction. Also, there cannot be repulsion between opposite-charges at short-distances, at variance with large-distance interactions.