I agree. That's a Juniper, & Junipers are definitely NOT indoor bonsai. I doubt your friend has had it for all that long, although as the previous poster mentioned, Junipers can appear green for a long time after they are, in fact, dying. But I don't think this tree is dead yet.
I don't know where you're located, but unless you live in the desert & fear the tree would fry, I would put this poor thing outside asap in a sunny spot & cease watering until the soil feels dry at least a 1/2" down. Another thing that bonsai do not tolerate is being watered on a set "schedule". They should always be watered by testing the dryness of the soil.
And if, with all your efforts, the tree does expire, don't beat yourself up over it. If your friend planned to keep it indoors ad infinitum, it was already doomed.
My body is a temple. Unfortunately, it's a fixer-upper.