A spy, an assassin and a telepath come together to pose as a family, each for their own reasons, while hiding their true identities from each other.
Located in the center of a remote island, the Abyss is the last unexplored region, a huge and treacherous fathomless hole inhabited by strange creatures where only the bravest adventurers descend in search of ancient relics. In the upper levels of the Abyss, Riko, a girl who dreams of becoming an explorer, stumbles upon a mysterious little boy.
When five lovely young girls who hate studying hire part-time tutor Futaro, he guides not only their education but also their hearts. Time spent has brought them all closer, with feelings growing within the girls and Futaro. As they finish their third year of high school and their last school festival approaches, they set their sights on what’s next. Is there a future with one of them and Futaro?
