S05E143: Trial #1

The next day, Tsuna's class receives two transfer students, Monta Hariyama and Himeko Hariyama. During the break, Tsuna is attacked by Lal Mirch of their time period who reveals she will be the observer of the Arcobaleno trials. Colonnello appears and reveals he is their first opponent in the trial. Colonnello chooses Tsuna and Gokudera to undertake the first trial. The goal of the first trial is to grab the button on Colonnello's headband. Tsuna and Gokudera are overwhelmed by Colonnello's traps and attacks. Tsuna tells Gokudera that fighting separately will not work and they must work together to defeat Colonnello.