While certainly attainable through pinpoint timing, you may find yourself waiting through several games before the opportunity presents itself, and further, that you have a hyper ready - and are alive to use it, something Kiriko is not notorious for being much of the time.
Simpler is to make use of cards like Forced Revival or Sealed Guardian to force characters into the 1hp threshold without needing to risk your own mortality and stars battling them down to it. Sealed Guardian is of particular usefulness because it effects everyone, and so long as you have a hyper handy, the pair used one after the other make the achievement a cinch. Play of the Gods can also be used to draw Sealed Guardian before Norma 5 and is worth packing if you don't run many other event cards it can choose from. In multiplayer especially, it tends to be used by players old and new alike for its relative cheapness, and is therefore good bait for others if you can't find it yourself.
Do, however, beware healing/damaging field events such as Air Raid, Bomber, or Regeneration, as these can easily ruin your setup if poorly timed.