Aika's story continues, she is now 19 years-old, 3 years older than in R-16 and 7 younger than in Agent AIKa. Strange phenomena have been occuring at a girls academy. Slowly but persistently the most cute and beautiful girls are joining an internal club, but instead of a sing-in they just get abducted by a strange being that takes control over them by some indecent means. By coincidence Aika was flying-by on her plane when one of this abductions occurred and she was attacked to prevent her from comming closer, but instead of repelling her, she is intrigued about the attack's origin and then the opportunity shows up when her late partners from R-16 decide to investigate those abductions. The story remains full of action and panty flashing that are a must in Aika's series. (Source: ANN)

Seventeen year old Nakaido Hirosuke is just your average high school student. One morning as he arrives at the train station on his way to school, he catches sight of a beautiful girl, Ajimu Yasuna, and immediately falls for her. The two of them get to know each other and become friends, but he can't confess his feelings and she is unsure of hers. As events and other people present obstacles for the potential couple to clear, their relationship begins to develop and their feelings become clear. (Source: ANN)

Yume Nijino has been accepted into Four Stars academy, home of the beautiful and talented S4 idol group. She and the other newcomers are determined to discover their talent, with a choice of specializing in beauty, singing, dancing, or drama. A tough road lies ahead of them, and they must rely on each other to overcome their weaknesses and develop their unique strengths. At the first-years' opening performances, Yume performs stellarly but faints and is unable to remember being on stage at all. Struggling to find her talent, she meets Rola Laura Sakuraba, and the two develop a friendly rivalry, working together to learn and improve. Though they have their differences, all the students share the same goal: to become the next S4 idol. But hard work and determination, along with teamwork, are needed if they want to join the elite S4.

Aika is a smart and athletic high school girl. She is so competent that she successfully passes the salvagers license test, obtaining a C-class license. Yet, she is young and hotheaded, so much so that Gota still treats her as a child. Due to this personality, no one is willing to hire her for salvaging jobs. Since she had taken the trouble to get her license, she decides to post an ad in her school to attract clients. She manages to get the attention of Erika, a daughter of a rich family and the leader of the treasure hunting club. She asks Aika to salvage something from the sea and Aika delightfully accepts the request. However, upon seeing the state-of-the-art submarine loaded onto Erika's private cruiser and discovering their destination, Aika realizes the terrible nature of her assignment. This results in a clash with a group of high school girls in the southern islands. Who is the mysterious girl named Karen? So begins Aika's newest challenge! (Source: AnimeNfo)