Quite the cog on that thing! I'd go to a used bike shop and see if they have an extra. Should be pretty standard. And be sure to
measure the chain for wear!
Taiwan made is very common these days; even my year-old mid level Trek mountain bike was made in Taiwan. Your bike appears to be from the late 80's or early 90's, from a Japanese company. Compare to
this.
If I recall correctly, Takara was one of many bike boom era companies that produced what might be referred to as "assembled bikes" with frames, wheels and components purchased and assembled from outside suppliers. Nothing special, but as the link says, probably better than a new department store bike. It looks as if you have friction shifting, so that will probably last forever and a half with proper maintenance.
Overall, not a half bad score! I hope you get years of service out of it, or a little tinkering and a quick buck if you so choose.
