Kenji Sakamoto, Yusuke Sato, Satoru Tanaka, Katsutaka "Jumbo" Yokoyama, and I arrived at K7 base camp on July 20. Jumbo and I planned to attempt the previously unclimbed K7 Central, while the rest of the team hoped to climb solid and beautiful rock in the area. However, during our first night, the liaison officer told us that splitting five climbers into two teams was not allowed: Kenji, Satoru, and Yusuke were due to leave on August 8, and the regulations required Jumbo and me to leave with them. The available time was too short for a peak of nearly 7,000m. Because of the extreme heat during acclimatization, and our limited time, Jumbo and I changed our objective to the southwest ridge of K7, which has a short approach and relatively little objective hazard.

On our first attempt we jumared two fixed ropes left just a week earlier by a Welsh team (see note below), and then started directly up the first tower. It’s possible to avoid this tower by a gully to the left, but we wanted to climb the ridge with a “sit start.” We swung leads for five pitches of excellent rock and then fixed our four 60m ropes, returning to base camp for three days of heavy rain.

When the weather cleared, we re-ascended the ropes. The first tower is composed of mostly excellent Yosemite-like granite, and after around 10 pitches up to 5.10 we found a cozy bivouac spot almost at the top of the tower. Unfortunately, there was little snow for making water: We made pasta and soup with lots of gravel.

Next day we climbed crack systems of various sizes, mostly on good granite. There were wet and icy overhanging cracks to reach a 5.9 A1 chimney. Before midday we arrived on the snowfield at the top of the first tower and made two rappels to reach the Jutting Ledge in the col behind [so called by the 1990 team that made the first attempt on this route]. We climbed the second tower on moderate ice, and when almost at the top found a ledge just big enough for our two-man tent. This time there was plenty of snow to melt for water.

On the following day we climbed beautiful and exposed rock, with solid hand cracks and offwidths. Two rappels landed us in the Japanese Couloir, which comes up from the right. Just after dark we found a perfectly flat spot to bivouac.

Next morning, we headed toward the Fortress (also named by the 1990 team), climbing a meter-wide and occasionally overhanging runnel of ice. After several pitches of rock, ice, and mixed, we followed an ice flute into the darkness, hoping to find a bivouac site. Instead, on the top of the Fortress, at around 6,300m, all we found was a knife-edge ridge. We rappelled, losing about 100m of height, until we found a small, icy ledge.

Just before dawn on day five, we were awoken by spindrift hitting the tent. The weather had changed, and the forecast was bad for the next three days. We decided to retreat before things got worse and rappelled the left side of the ridge to reach the 2004 House route. We descended this, trying to keep close to the edge of the gully as the small serac above continuously collapsed. Just before dark we reached a safe gully below the Jutting Ledge. The following day, one rappel landed us on the glacier, and we were in base camp by noon. Next morning, we all walked out to Hushe and were in Skardu the same night.

— Genki Narumi, Japan

Prior Attempts on K7's Southwest Ridge: The southwest ridge of K7 is one of the great unclimbed rock ridges of the Karakoram, and has been attempted on multiple occasions, most notably by Dai Lampard and friends (U.K.). With exceptional persistence, Lampard has now made four attempts on the route, from 1990 to 2022. In 1990 his team climbed 88 pitches over 18 consecutive days in capsule style to reach a high point of around 6,150m on the Fortress. Apart from 10m, the route was climbed free. He returned in 1993 and spent 32 days on the ridge, reaching the top of the Fortress at 6,300m (with pitches of British 6a) before retreating in a violent storm. In 2006 he made another attempt, experiencing appalling snowfall, and was equally unsuccessful in 2022. The route is estimated to be around 6,000m in length and almost 2,400m high. Narumi and Yokoyama may have been the first to climb the first tower integrally, though it was attempted by the 1993 team.