The Final Seal (最後の印) is the 153rd episode of the Katekyō Hitman Reborn! anime series.
Synopsis
Tsuna, with his Hyper Intuition, feels that Verde is nearby and finds Verde hiding in a nearby island. Verde declares his research is complete after gathering data on the Vongola Rings' Flames and states he will not need the Vongola Rings any more. He gives Tsuna the Arcobaleno seal as he has passed Verde's trial of Intuition. As they leave Verde's base, Reborn tells Tsuna he has passed his trial after showing his resolution to protect his friends in the previous battle and gives Tsuna his Arcobaleno Seal. With all seven seals gathered, Tsuna and his friends meet at Namimori Shrine. Using the ten-year bazooka, they are sent back to the future where Irie greets them and announces they shall train for the battle against Byakuran.