Years after the battle with Naiolo ended, strange news has reach Amakubo Yuri, the developer of ExS-TIA System. It's about someone who looks like Amakubo Kaede, her older sister whom she once fought and suppose to be dead, has been seen on a remote island. To ensure the truth, Yuri contacting Souma and depart together to the island immediately!

Story about Yuri, ExS-TIA heroine who doesn't has a single side episode, has been made. Story of Yuri and Kaede that more or less has been conclude in ExS-Tia 3 but you want to see more, also enjoyable to be played as the sequel to the original works.

[Translated from official site]