I believe it is a Pelargonium - commonly called Geranium.
But I am not 100% certain. The photo is not allowing me to see leaf details with any clarity.
Most of the geraniums (Pelargoniums) used in the potted plant trade have ancestor species from desert regions of South Africa, They will survive a dry spell during cooler weather. I have left some of mine completely dry for 2 or 3 months and they grew well in spring when I started watering them again. The larger the plant, the less water it needs in winter. Small plants might not store enough water, these will need to be occasionally watered in winter. They have lovely flowers all summer long.
They make an okay bonsai, more often used as kusamono than a tree worthy of being the focal point of a display. The do not have ''true wood'' like a deciduous tree, no growth rings. The trunks are more or less stringy bundles of fiber inside. But the fibrous stems are sturdy enough to last a number of years. They do not take bending older branches. If you use wire at all, wire the new growth before it is 6 months old. After that it will break rather than hold a shape. Clip and grow is the most common way to style them.
