As Sedna's power grows, a haze spreads out from the sea and covers the town. Even though Marin and Kanon have gotten stronger, they're no match for the darkness seeping its way into everyone's hearts. Kojima, Suzuki, Miyako... no one is safe.

As Nishida's plans of retaliation against America continue to unfold, Yushiro confronts his brother Kazukiyo in regards to his ambitions pertaining to the kai.

Marin and Urin used to be inseparable. Where one would go, the other would always follow. But now, Urin is walled off and locked away, beyond Marin's reach. Is this what Urin really wants? Will they ever see each other again?

Ataka and Kaburagi run into Yushiro by chance. After learning from him that Miharu's been taken by Symbol, they decide to try and assist him on rescuing her and storm an air base.

Everything is falling apart. Urin is missing... The sky is black... Marin can't shake the cold grip on her heart... Ghostly purple butterflies are swarming over the sea... And the eclipse, that blood-red ring in the sky, continues on without end.

The 3rd Experimentation Company elects to assist Nishida's ambitions. Their first task is to provide protection detail for the Prime Minister, but things quickly spin out of control.

Kanon needs to be 100 percent pure, but right now, she's way too evil. So, to help her in her quest for purity, Matsumoto gives her a treasure map. If she can find the mysterious treasure hidden on Kagero Island, it will grant her the pure heart she seeks

Nishida and Colonel Hayakawa meet to discuss the possible utilization of the 3rd Experimentation Company in Nishida's plans. Meanwhile, Symbol moves in to recapture Miharu.

Something dark and sinister was released from that stone coffin. Rain is pouring down, the seas are churning, and... a turtle statue just came to life?! His name is Matsumoto, and he knows the truth behind what's happening.

A year has passed, and Kanon returns to spend the summer on Amamiko Island. Although Kanon's life has completely changed, things on Amamiko seem to be the same as they always were. Kanon can't help but wonder... are things the same for Marin, too?

Kazukiyo meets with Nishida to discuss plans for influencing Japan's economy. During their conversation, Nishida recounts the tales of the Kugutsu… an ancient warrior clan that used large, biomechanical warriors known as the Kugai as weapons of war.

A Valentine's Day debacle spurs Takebayashi to seek greener pastures, and his fellow party members must find a way to convince him to stick around.

L and R have a dream that they made a wish to a genie in a bottle. Though it does happen occasionally that they have the same dream, this time the content of the wish differs and it throws them for a loop. Then Atom suddenly announced that their club...