Soul Hackers 2

You get a tutorial for these once you clear Arrow's Soul Matrix 1F. At any time past this point, head to Bar Heidrun from the City Map/while in Shinsando and select the option "Drink with allies". Choose who you want to hang out with and watch the scene to increase your Soul Level with whoever is present. The first time, you will also get this achievement (and you need to do them for the other achivement for doing 40 of them).