Ruqun
Samue
Plum Blossom Hair Clasp
Hong-Style Jangdo
Wanderer's Chest
reward is
Emigrant Hat.
Each of the items requires a specific east asian npc to be recruited to a company colony. The required quests are listed on the item pages. Once the quest is complete, the npc may randomly appear at the company colony. The east asian npcs stay for 1 real life day.
The quests are not repeatable and only need to be done by one character in the company. There are follow up quests for each npc, which seem to make the npc more likely to appear the next day. I was able to get 4 of the 5 npcs in a week, and found the other at a different company's colony.