S1·E15 I'll Cut Off the Shackle of Thorns!

Ikki and Rika engage each other in the Parts Wars with each other declaring their intent to win. Ikki eventually defeats Rika in the Parts War match and was the sole winner. Rika admits defeat and decides to help Ikki to further train him in the use of Air Trecks by strapping weights on his body. Ikki and the rest of Kogarasumaru, in their Spring Break, train together for the first time as a team in order to improve their Air Treck skills. Meanwhile, an unknown wave of AT Team disbandings were apparently being caused by Agito on his own during the Parts Wars between Ikki and Rika.