Routes

Routes is a science-fiction visual novel and the fourth entry in the Leaf Visual Novel Series, taking place in 21st-century Japan with Nasu Souichi, the main character whose a perfectly ordinary high school student and tries to do as little as possible every day, sleeping through most of his classes, only ever to be woken up by his friend Yuasa Satsuki. They believe they are living in a peaceful time, where no large wars are occurring.
However, these peaceful days are over when several large ships disappear in the sea one after another, almost instantly and with no explanation as to why. A strange woman named Lisa Vixen suddenly appears, leading to Souichi getting involved in the case.