Handkerchief

Handkerchief is a Tool that improves the odds of a positive outcome in Social interactions between Disciples, meaning that you'll see more positive social Moodlets like "Heart-to-heart Talk" and less arguments and fights. This indirectly improves the Mood on average. 
Using higher quality materials like Demon Beast Hide improves the Attractiveness and Tier, but does not boost the item's bonus, therefore making it fairly pointless.
==How to obtain==
Handkerchief can be crafted at a Handcraft Station by an Outer Disciple with the Crafting task activated. Exact material can be specified by right clicking the item in the crafting menu.