Crossed the Sunwapta early in the morning of August 19 and made our way over Woolley Shoulder to the Lloyd MacKay hut. On Aug 20th we climbed up to our high bivy on a ledge about 50 meters south of the start of the technical climbing in the Japanese Couloir. We started climbing the couloir at about 7am on Aug 21. Started too far right and had a few hard pitches (5.7-5.8) before getting back on route. The top two pitches (100m) were WI2 snow and ice. Got to the summit ridge about 4pm. The bottom 1/3 of the 20m notch on the summit ridge was melted out and there were only a few small cornices on the last 100m of the ridge. We traversed the ridge and arrived on the summit at about 6:30. Stopped for no more than 2 or 3 minutes due to late hour. We got back to the top of the couloir at about 8:15. Had light for the first 3 raps down the couloir and finished by headlamp getting back to our high bivy at about midnight. It was just beginning to snow. 17 hours bivy to bivy. The next morning was a difficult descent over snowy ledges (snow covering very loose rock). Got back to the hut around 6pm. Walked back out over a very snowy Woolley Shoulder on Aug 23.