When high-school student Souji Kushiki, an academic achiever and talented athlete from a well-to-do family, returns home from boarding school, he finds that his sisters Harumi, Youko, and Saki have changed. Their strangely clingy behavior borders on the inappropriate and bizarre, yet Souji just brushes off their odd behavior at first.

However, when Souji arrives at school the next day, he learns that, during the summer, one of the students in his class was pushed to his death in front of a subway train. And what's more, two other students were stabbed by an unknown culprit. Are the victims linked, and could Souji's sisters have anything to do with the murders?

From Yen Press:
Kyon is your ordinary high school freshman who has long given up on his childhood dreams of encountering the fantastic and supernatural, or so he thought.
From the very first day of school, his classmate–the beautiful but eccentric Haruhi Suzumiya–makes it very clear that her only desire is to meet aliens, time travelers, and psychics! A chance conversation between the two inspires Haruhi to form the SOS Brigade, a school club created for the sole purpose of getting these supernatural beings together. The initial members consist of the mute bookworm Yuki Nagato, the timid but voluptuous Mikuru Asahina, and the polite and ever-smiling Itsuki Koizumi. By the end of this first volume, Kyon quickly finds out that these seemingly “helpless victims” of Haruhi’s are actually members of secret organizations–both futuristic and alien–keeping watch over Haruhi as she is the pinnacle of some major calamity on the horizon.

From Yen Press: If you thought the SOS Brigade’s adventures couldn’t get any more outrageous…you’ve never met Haruhi-chan! Nagato has gone otaku! Asakura is her pint-size prisoner/plaything! Mikuru’s so cute she turns into a sheep! You’ll find plenty of gags and guffaws as Haruhi dives into the world of four-panel and short comics!!

From Yen Press:
Yuki Nagato, the shy president of the literature club, has never been very sure of herself around other people. But around Kyon, the only boy in the tiny, three-person club, Yuki finds herself faltering even more than usual. For Kyon, and for her precious club, Yuki must find her confidence and let her true personality shine! Enjoy taking a fresh look at your favorite characters in this brand-new story set in the world of The Disappearance of Haruhi Suzumiya.