Some say a home is where your heart is. Others say that a home is where you send people whose brains aren't functioning quite properly. So, when Kazunari Usa's parents send him to the Kawai Boarding House while they work abroad, it may take a while to figure out whether this is really his new home, let alone what kind of home it is. On the one hand, his new roommate is a pervert and a masochist who peeps at girls' schools, while his new landlady thinks leaving a variety of weapons lying around the girl's area is a proper form of feminine protection. And when it comes to the trouble-making college girl and the perpetually grumpy working woman… well, let's just say that those two have some serious issues to work out. On the other hand, Kawai is also home to Ritsu Kawai, who stole Usa's heart from the first second he saw her on his first day at his new high school. And that alone may just make living in this strange new house worth every second it takes to learn the complex rules of The Kawai Complex Guide to Manors & Hostel Behavior!

Does the new girl in Riki Naoe's life need his help, or is she actually trying to kill him? After a chance encounter on a rooftop brings the enigmatic Saya Tokido into the Little Busters' world, the only thing that's certain is that trouble is sure to follow. As if saving the lives of his teammates wasn't enough of a task to handle, now Riki must also untangle a web of new mysteries that seem to be rooted in his own personal past! Who are the Dark Executives, why do they want to keep Saya and Riki apart, and what is the nature of the secret treasure that Saya seeks? Sometimes, answers lead to even more questions as Riki and the Little Busters discover that they weren't the only people drawn into Kyousuke's artificial world in LITTLE BUSTERS! EX!