The Twin-Tail Club is just about ready to start, and Twoearle gives the club's classroom her own touch. With Ultimaguil on the ropes, some new reinforcements arrive to try to turn the tide, but the Twin-Tails add a reinforcement of their own.

Erina's first outing as Tail Yellow does not go as expected, and she later confides to Soji that she may not be qualified to be one of the Twin Tails. While Soji tries to work with Erina, Aika must deal with an attack from Leviaguildy and Krakeguildy!

Student council responsibilities, school work, and Twin Tails activities are taking their toll on Erina, and when her mother pushes her to straighten up, Erina pushes back. When Mikoto is unavailable, Soji must secretly escort Erina on a shopping trip.

Spider Guildy, a formidable Elemelian officer, arrives to deal with the Twin Tails. Their fierce confrontation ends in a draw, but a surprisingly intense attack leaves Tail Red dazed.

Soji awakens to find himself in the form of Solar Metca, a slightly more grown-up version of Tail Red. He also comes up short in combat with an Elemelian, and the others become concerned about him...