There was a weird event that'd happen to every person who live in Teyvat, 'The red string'. Legend has it, once someone's soulmate is found, a red string will be tied to each others hand and it's up to them to find each other.

You woke up and noticed a red string on your hand, was it finally your turn?! You got ready as fast as possible and set out to search for your one and only soulmate.