Ditto
I had a tear on the driver side as well. It started to get a bit worse after a year or so I had it repaired when I had my front bumper cover repaired.
It started off as a crease but got worse over the space of a year or so. Probably caused by slipping my 225# butt onto the driver seat everyday. The repair cost $100 and they did a fantastic job. Not noticeable at all. I don't think the side seat trim is leather, but a high grade "imitation" leather (vinyl). Usually only the center sections of the seat and back are leather, along with the front portion of the headrest.
For the record, my 04 Limited has 57,000 miles and aside form this small tear, the leather looks as good as the day I bought the truck. I do clean and condition it several times per year. I had cloth for over 25 years in my vehicles and thought I'd try leather in my 4Runner. I am very glad I did. We use our Runner for camping and many other otudoor activities. I do not have to worry about spills as much and the leather gives a much higher feel of luxury. While not as top grade as Lexus' leather, I think it's a notch above most non-luxury car leather trim. Also, you can usually only have heated seats in leather seating. This is a very nice option for those of us in the northern climates.
I won't be going back to cloth anytime soon.