From the description, it's supposed to be exchangeable for Sasaki partner scrolls, but I think it wasn't implemented properly. Hope they fix it in the coming updates. Gonna get them in the mean time, since I'm 2 scrolls short of awakening.

Ok so there is an actual use for it in game right now. I must've skipped through it because the Sasaki NPC only keeps saying "00000000000s" to me.