The characters you recruit in Genshin Impact have a story behind them. They have a unique reason in the world and a rich backstory that you can unravel with a little bit of time and patience. To do this, you need to raise your friendship experience with them, and to do that, you have to do various events. There are a handful of specific ways to do this in the game, but it’s only after you raise your Adventure Rank high enough to unlock Daily Commissions.
Daily Commissions, dungeons, and random events scattered throughout the world provide you with Companionship EXP. You use these experience points to increase the friendship for the characters in your party. The more you gain and level, the more you learn about that particular character. You can review the quest you’re about to finish to see if it provides you with companionship EXP.
All of the characters have friendship levels, so you can expect to work on repeating dungeons and other events you find in the world with new characters to increase these levels. It makes the world a bigger place in Genshin Impact. The friendship system was shared by developers miHoYo at the beginning of 2020, creating it for players to care about the companions they had in their party, and to have it so players could make critical decisions with them during quests. These mechanics may appear later on, and developer miHoYo did say increasing friendship levels would pay off in the long run, hinting at making them a worthwhile endeavor to level up early.