Click the character portrait to reveal the merc's gift and friend of choice.
The "Friendship System" is an in game system that allows you to bond with other character classes unlocking various titles, the bonded merc's dance, and when a specific class is bonded with your specific class it will unlock a special hold skill that when toggled on when in a party with the bonded class will trigger if both persons have the toggle set.
Building friendship can be done by talking with the 6 daily rotating mercs or summoning a merc and performing specific tasks such as departing on missions with a merc and completing the selected task. talking with a merc. and giving the merc gifts.
You can summon a merc that is not in the daily rotation by simply approaching the pupper at the gift shop stall and selecting "Summon Merc". This allows you to build bond with the character regardless if they are present or not naturally. You can also purchase gifts here to give to your merc. Matching certain gifts with certain classes gives a boost to the received bond per gift. (Picture attached below)
Behind the gift shop you can depart for a battle with a merc to increase friendship bond.
This is a picture of the bond meter maxed out for the day.
When you approach the desired merc and initiate "Chitchat" you can talk about certain topics that will increase your bond.
Talking with mercs increased the amount of topics to talk about.
These topics can used across all mercs.
The "Chitchat" topic can be used 4 times daily per merc, all other topics are 1 time use per merc and do not reset.
Then you can give gifts to the merc and increase the bond meter. Utilizing the "preferred" gift will net you the most bond per gift.
("Gifts" shown below)
The most simple way to increase overall bond levels is to "chitchat" with the merc the 4 allotted times and gift the merc their preferred gift 4 times, and depart for a friendship mission to max out your bond status daily.
1 mission with the merc is equal to 4 of the preferred gifts. So if you wish to skip the mission, gift the merc an additional 4 gifts to replace running the mission to max out your bond meter for the day.