This involves having two characters that love each other (admirer).
Explanation for campfire stories, ignore if you understand the system:
*** Spoiler - click to reveal ***This is done through the campfire system where once per expedition in the bottom right corner of the screen the campfire bar fills up as you progress. When selecting the campfire you will have the choice of four randomly selected cards from a pool determined by the crew you have selected. The unique cards for each crew member must first be unlocked by completing adventures to aquire booster packs. The gold coloured personal campfire stories are the easiest way to build relationships between your crew.
The easiest crew I found to get this achievement involves Harry Walker (scout). It is important to select the personal campfire stories in early expeditions as the relationships will take subsequent expeditions to build. Save scumming may be used to ensure you get the campfire stories you need, typically saving a node before the campfire is available.
Personal campfire stories:
Harry: Select a crew member. In subsequent expeditions choose the option where Harry apologises.
Other crew members: If struggling to save scum, Kiwi, Kwame and Yvonne's stories have the ability for a targeted crew member to admire them; Yvonne will admire Earl if he is present; Hildegard can admire a targeted crew member.
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