Yamaguchi Kosuke (山口 康輔) is a finswimmer who has attempted SASUKE four times. He debuted in SASUKE 12, where he timed out at the Rope Climb and his run was all cut. After, this, he start to train with the rope and the results are showed, as he clear the first stage in SASUKE 13. He was slow in the second stage, and he timed out before lifting the second wall of the Wall Lifting. His final appearence was in SASUKE 14, where he once again cleared the first stage, this time with over 20 seconds on the clock. He managed to clear the second stage for the first time, doing so with only 1.7 seconds left. In the third stage, he cleared the Rumbling Dice, but he landed poorly in the platform and fell into the water. After 9 years and 15 tournaments later, he made a return in SASUKE 30.
|12||60||Failed Rope Climb (First Stage)||Time Out, All Cut. Shown in his Sasuke 13 profile.|
|13||87||Failed Wall Lifting (Second Stage)||Time Out. Cleared the first wall but timed out before he could lift the second one.|
|14||88||Failed Rumbling Dice (Third Stage)||Yamaguchi finished the obstacle, but landed poorly on the platform and fell off.|
|30||2985||Failed Hedgehog (First Stage)||All Cut.|