Chicory: A Colorful Tale

This is not so much a guide but more of a helpful tip. This should unlock after delivering the first round of letters for Artichoke with the last one being to Taiyaki in Brekkie.

For the full list of delivery locations refer to the guide for Such Great Heights (Developers are obvious fans of the band Postal Service).

Once you receive notice that your mailbag is empty return to Artichoke in Dinner. Speak to him and he will give you the next round of letters and the mailbag costume. The achievement should unlock at this time, but if it doesn’t try speaking to him again. This is what worked for me.