The time has finally come for the fight that will determine the fate of Catia and Earth. The girls find themselves coming face-to-face with each other and with what they want deep down inside their hearts, even though they share the same strong desire to protect what's right. As the fighting gets fiercer, emotions race and wounds from the past open again, and events take a turn that no one could expect. With the beautiful Earth to their backs, what will happen to the young men and women that scream of love? Where does Earth's fate lie?!

The Catians are in trouble. Kio and the gang are trying to prevent disaster by doing whatever they can, but they keep getting cut off at every turn due to the strategies of Dogisia. Their emotions race, brought about by the spur of the moment situation they now find themselves in, and how they feel for each other starts to cause conflict. Amongst the chaos, it is Kio, who stands at the center of all of this, that will have to use his courage and decision making skills to make it through.

The girls are getting ready for Christmas. Manami and Aoi, fearful of Elis and Kio getting any closer, prepare a plan to once and for all make Aoi part of Kio's life. Meanwhile, on the Catia front, they prepare to give a special present on Christmas, but in the shadows sits Dogsia, with a smile on their face, ever bigger than usual.

Below the full, starry sky, each of them listened to the same song from all over. A very gentle song, with a hint of loneliness. Even if everyone has different feelings for each other, in that moment, they all shared the same emotions. A tale which connects the past to the future is told with the enchanting song. Everything started with the first Catian Assistaroid, Rauri, coming to Earth.

The sharp sounds of gunshots echo through the beautiful, untouched Yanbaru mountains, located in Northern Okinawa. The two beauties start a fierce battle with their pride and dignity on the line. They each see each other as best friends, and sometimes as rivals. They don't want to lose what's important to them, and they fail to realize the feelings of sorrow that the other feels. What is it that made them fight in the first place and what will become of this battle? In a fight that literally strips them of everything they have, a battle begins to see which women will stand on top.

The new semester just started, and Kio's class erupts as an unlikely surprise befalls them. Bizarre transfer students appear before them: an alien, a robot, a extremely wealthy ojousama, maid soldiers. The boys of the class have their hearts stolen, and the girls seethe with jealousy. The spiral of love is fierce, and chaos comes, whether they want it to, or not.... And another event comes to push the event even further. Attractive girls in swimsuits await Kio and his friends on the beautiful beaches of Okinawa.

Elis is having more frequent episodes of her mating season. Eventually, she drags Kio's movie club into the mix and starts to turn their completely normal film into a very "adult" love romance. Meanwhile, Aoi and Manami visit the Virtual Room on Catiaship. The two of them are capable of virtually creating any situation there, but will they be able to resist their overflowing desires?

Continuing from last episode, Kio finally finds himself in bed with Elis, now completely within her mating season. Able maids take care of their every desire, and a girl in a sexy micro bikini storms the ship, fueling chaos everywhere. Just what will happen to Kio and Eris? Meanwhile, Aoi and Manami, in their bathing suits showing off as much skin as possible, attempt to save the two, but a mysterious freak with a hidden camera watches them from the shadows.

Elis' mating season is upon her, something which befall those who have evolved from cats. Elis goes after Kio, but Aoi and Manami try to desperately stop her, only to falter in the face of their own desires. The four of them continue their steamy exchange, and eventually find themselves in Nakano Broadway. Meanwhile, the cat-ear, cat-tail worshiping organization, the Cat-Ear Corps: Underside of Kitten Paw, begin their operation, "Unyaakun." Unyaa!

The Catians come to the table to negotiate opening diplomatic relations with Japan. Using their cute, glamorous, and sexy bodies as weapons, they come armed with an invincible fleet of school swimsuits, taking in the staffers at the Ministry of Foreign Affairs with their charm. Meanwhile, Minami and Aoi start living with Kio and Elis in the Kakazu residence in order to hide themselves from the organizations they were once with. It seems as if a rocky road awaits them as a complex web of feelings develop between the four, and feelings of temptation run throughout the household as the three beauties, plus Assistaroids, settle down together. What will happen? No... What will you do about this, Kio?!