Whakarāpopototanga
Ko te Grisaia: Phantom Trigger ka puta i muri i te trilogy o te Grisaia o naianei, me te whakaatu i tetahi roopu toa hou me tetahi toa hou.
Whai muri i te raru o Heath Oslo, ko te noho o te US-Japanese anti-terror organisation CIRS kua noho hei kaupapa mohio mo te iwi. Kua hanga ano a CIRS mai i te timatanga, a ko ana mahi tino huna i huri ki tetahi umanga hou: SORD (Social Ops, Research & Development).
Ko te whainga o SORD ko te whakangungu i te reanga hou o nga kaimahi ki te tiaki i te whenua mai i nga whakatumatuma a meake nei. Mo tena, kua whakatuhia e te whakahaere he raupapa kura ki runga, ki raro hoki o te motu. Ko te Whare Wananga o Mihama, he nui ake, iti ake ranei ka pirau i muri i tana katinga ohorere, he kaupapa hou hei 'kura whakangungu tohunga'.
Ko tenei whakaurunga hou o Mihama Academy he kainga mo te roopu tauira kanorau, e mahi ana ia ra ki te whakakoi i o raatau pukenga rereke - i etahi wa kei te mahi. He kaipupuhi ko Fukami Rena (ingoa: “The Rabid Dog”), he kaipupuhi ko Shishigaya Tohka, he tohunga mohio ko Kujirase Christina Sakurako, he ninja ko Ikoma Murasaki, ka mutu, ko Aoi Haruto, to ratou kaikawe. Inaianei kua tukua e te kura whakangungu tohunga a SORD nga kotiro kino e haere ana ki reira me nga pu me nga kariri i runga i te ingoa o te whakamarumaru o te motu.
Ma te kore e aro ki o raatau ake haumarutanga, ka tohe tonu enei tauira ki roto i nga mahi whakahaehae kino - mo te pai o te rangatiratanga.