I hate to be the bearer of bad news. Really. But Ive read too many times that junipers have been dead a while when they get to that point. Theyre slow to show it. Im sorry. Idk where it was, but they cannot live inside. Maybe someone will have another opinion. But thats what most will say. Also bonsai must be in free draing soil, not potting soil. There are many threads about soil here. They must have a hole or two in their pots. Muddy or wet soil kills trees.
If you want indoor bonsai, get a ficus or shefflera. There are others, almost all tropicals. Someone with more experiance will be able to help more, Im just passing on basics Ive learned in the last year reading about bonsai and keeping trees..