As Akane, Aoi and Momo begin their first day to New Oshima Academy, Akane, who was using the Vivid System as she was running late, ends up meeting kendo club member Wakaba Saegusa, who becomes shocked when she counters her attack. After Akane and Aoi officially transfer into Wakaba's class, Wakaba chases after Akane demanding a rematch until she ends up bumping into Momo, deciding to take her to the nurse's office. As Wakaba and Momo get acquainted, Akane overhears how Wakaba wanted a rematch to prove she's the strongest. After her dad tells her to think about what 'true strength' is, Wakaba formally challenges Akane to a serious kendo match, which reminds Wakaba of how fun kendo used to be for her. Just then, their match is interrupted by the appearance of a serpent-like Alone. As Wakaba comes to realise what true strength is from watching Akane and Aoi fight, she asks to fight alongside them, granting her her own ignition key. As the mysterious girl powers up the Alone again, Akane and Wakaba dock to become Vivid Green and defeat the Alone.