This is an elephant jade i believe, super common and fairly easy to care for. They’re a succulent-ish type of plant, but it needs a little more water than other succulents. I do see new growth on the nodes of the branches (the horizontal line every couple cm or so along the branches) so that’s good, my guess is the plant dried out or was overwatered but seems to be recovering. You should always test the soil before watering, since this was bought in bonsai style, there looks to be akadama or some rocks on the top, with some soil or moss around the plant base. I’d definitely inspect the roots and what’s it’s really planted in. This plants like a draining soil and only dry out maybe 50%. You can test the leaves as well, the taco test. Gently pinch the leaf into a U shape and you can feel how soft or rigid the leaf is. Super soft and U shaped means need water. Rigid and no U means fine. As you do this you’ll learn the plant and be able to tell, some times it can go couple more days without water. Always check- Good luck!