Leo's letter:
Man life without you is strange i mean since we were kids we always had a special bond,i hope you remember that!we would always talk about our future and who we were gonna marry and things like that remember Donnie!whenever you needed help i was there!just like you were for me!

Man i miss you so much!and Sensei if we write letters to you,you will reserve  them and come home I've been texting/calling April too but she doesn't answer!she's probably trying to process all this i mean she told me one time is that she would do anything for you,FUCK! Oh snap i cussed please dont tell Splinter he would kill me but i wanted to say..."Watashi wa kyodai ga koishi yo!"I miss you brother in Japanese remember we use to talk in Japanese whenever we trashed talked Raph!anyway i hope your safe Donnie see you soon!
                   Sincerely,
                                    Your leader Leo