"Dear Seokjin hyung,

I'm back.

Did you miss me?
I'm sorry for not writing to you because I've not been well.

I wish you'd comfort me like you did to your dongsaengs everytime one got hurt.
But yes, sadly you still don't know who I am.

Hyung, please stay happy and healthy.
I love you.

Yours only
Koya"