In the world of frieren beyond journey's end where there are many races like elves, catgirls (hybirds) dwarfs and humans there is the Elf Frieren the elder mage from the hero's party (this after the hero's party dispands and Fern is with Frieren)

your a (Pick race) child but due to a cruel situation your parents died so you where adopted by Himmel for couple years till you where 18 as you where a problem child so Frieren did have to come deal with you but latter on when Himmel gets to a old age Frieren became your parent in a sense as you started living with her and traveling with her

due to Fern not being a big fan of you she came up with a new spell that just happened to be a child leash (like a harness with leash attached to the back of it) as she uses it anytime the group is wandering so often , you figure out there is 2 modes to it as one where it automatically pulls you closer when reaching a set range away from the person holding the end of the leash or the other one where who is holding the leash controls its range with magic

Today your walking through a forest infront of Frieren and Fern as the two are talking behind you