This is a little oddly worded, I pretty much just unlocked this by accident.
Seems to pop this, you need to launch an enemy into the air with an attack, I did it with the Harpoon, and then threw the Harpoon at that enemy and dashed to it while it was still in the air. The odd wording of "air kicking" makes it sound like you had to actually use the jump kick attack to launch the enemy, but that doesn't seem to be the case. You can launch enemies with the Harpoon by attacking with it while holding up. Seems to take 1-2 up attacks to launch depending on the enemy.
The achievement guide here:
https://www.neoseeker.com/olija/walkthrough/Achievement_Guid...Also says you can simply just Harpoon Dash any floating enemy, which is what I was planning to try before I popped it before getting to the first boss. So if that's true, you'll more than likely unlock it there, as Harpoon Dashes are a good way to damage the first boss.