One night, Shihou Souma and his childhood friend Katsuragi Marina are walking in a park after school, when human-like monsters suddenly appear. These monsters, seeming to come from another world, start attacking and raping people, to absorb magical power from them. In this chaotic situation, Amakubo Yuri, Souma's school infirmary doctor, shows up and givs ExS-Device to Marina. Using the device Marina transforms into ExS-TIA and fights the monsters. [Translated from [url=http://lusterise.nexton-net.jp/product/exs-tia/intro_story.html]official site[/url]]

Peace has returned once again after resurrected Jinevra was defeated. Riesz goes to visit to her hometown in the other world to check it out after returning from her trip. Meanwhile, Marina and Souma enjoy their lives as lovers as peaceful days return. However, the monsters appear once again. Then, Katsuragi Marina transforms into ExS-TIA once more and defeats the monsters. Marina and Souma continue fighting to protect everyone. Suddenly, another of the Four General, Naiolo, appears before them. Despite countless battles and accumulated growth, ExS-TIA is at mercy of Naiolo's overwhelming power. With the power from her bond with Souma, Marina somehow manages to hold out. How will ExS-TIA fight against the new formidable enemy? The curtain of another battle has risen yet again. [Translated from [url=https://www.dlsite.com/pro/work/=/product_id/VJ013862.html/?locale=ja_JP]DLsite[/url]]

After defeating Jinevra, Souma and Marina lived the normal life, until, one day, monsters from another world invaded again with a new main antagonist - Garzom. Moreover, Riesz, a knight from another world and a new harem candidate for Souma, appears too. This ExS-Tia 2 comes with new battle system and new types of corruption. Let's see whether you can achieve the ending you want and will Marina get jealous of the new harem member?

The World's peace restored once again after Marina (ExS-TIA) and Riesz (ExS-TIA Chevalier) defeat Garzom. After that, in the spring break, Marina and Riesz go on overseas school trip. However, Souma could not go because he need to attend supplementary class for the bad results in his final test. While Marina and Riesz gone overseas, Jinevra revived as Jinevra Ω seeking for revenge against ExS-TIA and start the invasion again. Souma then ask Azarin, who get ExS-TIA power, to fight together against this new threat as ExS-TIA Magica.