How to Say Goodbye~ Kagehina Soulmate AU

In this AU, a large majority of people have soulmate marks that are permanently tattooed into their skin with the final words of their soulmates. There is also a small chance that they don't have a mark, and never meet their soulmate or never speak to them.
I got this idea from a tumblr post and decided to make a Kagehina fanfic with at least .1% Daisuga for my friend.
This is still to be fully planned out and a WIP
I have no idea what this plot is going to turn into