The Strongest Seven is the 142nd episode of the Katekyo Hitman Reborn! anime.
Back in the past, the 7 Arcobaleno are heading to Namimori to present Tsuna and his family with their trials. Meanwhile, in the future, Shoichi Irie is telling Tsuna and his friends the details before sending them to the past. He reveals that although months have passed in the future, only three days have passed in the past. He warns them that they should not tell anyone what happens in the future for fear of affecting it. He also tells them that the Arcobaleno Trials are a week long and must be completed without fail. Using Irie's device, they are sent back in time. Everyone resumes their normal lives. The Irie Shoichi of the past receives a letter from himself that tells him to place the Ten Year Bazooka under the Namimori Shrine. Gokudera and Yamamoto arrive to Tsuna's house where Reborn informs them that the Arcobaleno Trials involve all of Tsuna's Guardians. He then explains the background of each Arcobaleno and reveals they each have a special ability.