The doomed Boeing 747 had begun the hour-long flight from Japan's capital to Osaka when it crashed into a mountain about 120 kilometres northwest of Tokyo on August 12, 1985.
In all, 509 passengers, including a dozen infants, and 15 crew were killed in the accident. Just four passengers survived.
Bereaved relatives of victims make an annual pilgrimage to Osutaka Ridge, along with JAL president Yoshiharu Ueki who will walk the trail to a memorial service near the crash site.
Television footage showed some victims' relatives starting their climb up the steep mountain trail before dawn.
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Some blew soap bubbles to pay tribute the children who died in the accident, their names included on a stone memorial listing the victims.
"When I come here I feel like I can see her directly -- it's like she's in front of me," an 81-year-old man who lost his daughter told local media.
"Thirty years is a long time, but honestly I feel as if it happened yesterday, and the memories were stirred again this particular year."
The crew quickly declared an emergency and fought to regain power over the aircraft which had become "uncontrollable". It crashed into the mountain at 6:56 pm local time, about 45 minutes into the flight.
It was later determined that the bulkhead burst, rupturing hydraulic systems and leaving the plane uncontrollable.
A government-appointed investigation panel blamed the accident on improper repairs on the rear bulkhead seven years earlier.
In 1988, local police served papers on 20 people from JAL, the transport ministry and Boeing on suspicion of professional negligence resulting in death and injury.