Isuja has one rocky moon of rather small size, which was originally a small dwarf planet that was then captured by Isuja's gravity during the early formation of the solar system. It is 0.844 times the mass of Earth's moon, so it's only 0.869 times our moon's radius. It orbits 193,848.98 kilometers away from Isuja (on average), which is close enough that an Isujan "month" is quite short: only 8.864 days pass before the moon returns to its original phase.
Isuja's moon is very prominent in the night sky of Isuja. In its full moon stage, it is 2.7 times as bright as Earth's moon, and it appears 1.72 times the size.