Heavy Transport aircraft Captain reported encountering wake turbulence at FL320 from a preceding Heavy aircraft in RJTG airspace.

Narrative

This report is being submitted to explain the circumstances during a wake turbulence event prior to entering oceanic airspace over Japan. After extensive weather avoidance enroute our aircraft experienced a few short moments of moderate turbulence which then led to the aircraft immediately rolling into a bank up 35 degrees before the PF (Pilot Flying) could intervene by disconnecting the autopilot and safely returning the aircraft to wings level on altitude. The quick actions prevented the aircraft from an altitude change of less than 100 feet. We continued to stay in light-mod turbulence. The PF requested an offset from the track in the event it was wake turbulence from an aircraft 25 miles away and 1;000 feet above. Tokyo denied the request. In my concern for another event I unintentionally misinformed ATC we experienced severe turbulence possibly due to the aircraft ahead of us (I wasn't sure at the time whether it was due to the aircraft or CAT (Clear Air Turbulence). In reality the aircraft was controllable and the turbulence wouldn't be considered severe.) With that urgency ATC gave us an offset of 2 miles right of track and we continued with this offset during the oceanic crossing behind the other aircraft. No further turbulent episodes.The wake turbulence may have occurred when the heavy aircraft ahead of us had turned to head east from the north. My mistake in reporting the turbulence as severe instead of wake or moderate came from the urgency I felt for the situation recurring and possibly becoming worse as well as concern over the altitude deviation; which in retrospect; was minor.PF's immediate suggestion for the offset was helpful and we maintained the 2 mile SLOP (Strategic Lateral Offset Procedure) across oceanic airspace.