The two assassination challenges required for this achievement are Sushi, Honshū Style
and Daisy, Daisy
. There is another challenge for target Erich Soders that involves the robotic arms called (Not) Human Error; that method does not
contribute to this achievement.
At Hokkaido mastery level 12 you unlock the kitchen as a starting location. You can use this to get a head start on the Sushi, Honshū Style challenge. Also, keep in mind that you do not need to do both challenges during the same run, nor do you even need to finish the mission in order to unlock the achievement. Whichever one you leave for last, the achievement will pop after the kill, at the same time you see the challenge unlock.
All credit for the videos goes to the marvelous MrFreeze2244. In each he starts at the default location without any loadout items, which is the case until you reach Hokkaido mastery level 20.Sushi, Honshū Style
(which is a reference to HAL 9000 in 2001: A Space Odyssey