This is NOT a bonsai.
But it is also a good example of what can happen to a plant in the same small pot for five years without reppoting. Weak new growth, pale leaves, bad drainage, so...
Took it out of the pot this morning and almost had an heart attack.
Don't let it happen to your bonsai.

I've seen worse. We inherited a number of trees some months ago that had not been touched for probably 9 or 10 years. Most of them were half put the pots there was so much roots.