This was my version of the ending of REBORN!. This would happen right after Reborn leaves after Tsuna tells him that he doesn't want to become the Tenth Boss of the Vongola.
Tsuna goes to school and lives a normal day, but there is something wrong. He felt the absence of Reborn in there. He new he was never going to see him again due to his answer. Sad because of this, he goes to the School's roof to think. When he opens the door he sees Hibari in there waiting for him, sitting in the floor. "Where is the baby?"-Hibari said, Are you refering to Reborn?...he went back to Italy...-Tsuna replied with a sad voice. "Tch, that's too bad, i wanted to fight with him, at least i got you here..." -Hibari says as he pulls out his tonfas, Tsuna doesn't reply and looks down, "S-sorry, Hibari-san, but i'm not feeling well right now..."-Tsuna says.
"...Then i'll leave you" -says as he walks towards the door- "If you are feeling down, then i won't get a good fight from you, you and the baby are