Yuichi's not-very-restful summer vacation came to an end, and the new school term isn't looking much better. Immortal demons are trying to kill him, his new teacher is a superpowered sociopath, and all kinds of bizarre events are happening around the school. What does Kanako's new novel have to do with the bizarre goings on at Seishin High? Once again, it's up to the world's strongest little brother, and his highly delusional sister, to find out!

One day, first year high school student Yuichi Sakaki suddenly awakens the power of "Soul Reader" within him, and he can see words above peoples heads that describe their true nature! With just a glance at the people around him, he sees crazy things like "Zombie", "Witch", and "Vampire"... That would be bad enough, but then there is "Serial Killer" Natsuki Takeuchi walking straight toward him... Nobody would ever believe him! Well, except for his older sister Mutsuko: This kind of stuff is right up her alley.

Yuichi hasn't yet unraveled the secret behind his magical sight, but the end of his first school term is still as busy and can be! He's got survival club activities led by his big sister Mutsuko, early morning combat training with the serial killer Natsuki Takeuchi, and a first date with the vampire Aiko Noro (with his little sister tagging along, for some reason). Then, in the midst of it all, Aiko reveals that her big brother Kyoya -- whose world domination-plotting middle school syndrome has been growing worse and worse lately -- has gone missing!

The Divine Vessels War is reaching its conclusion. But with Soul Reader gone, Yuichi wants nothing more than to drop out! But will he really be able to go back to the normal life he's always wanted? And if he does, will Mutsuko ever speak to him again?!

Between a secret battle to reassemble a dismembered evil god and a threat from destiny-altering beings waiting in the wings, the world's strongest little brother seems to have enough on his mind. But there's even more waiting in store for Yuichi Sakaki, and things are about to get more chaotic by the week. Soon, a yakuza gang is stalking his little sister, a demon doll is stalking Aiko, an overzealous archer is stalking him... and that's only the beginning!

Yuichi, and the survival club are finally heading off for their summer training camp, to a luxurious villa in a remote seaside resort. Will anime-style swimsuit episode shenanigans ensue? If his big sister has anything to say about it, yes! But while the gang enjoys some much needed fun in the sun, a darker plot lurks just offshore. The world's strongest little brother is about to face his greatest challenge yet!

A SECRET NEVER TO BE TOLD... To rest and recuperate from their set of life-threatening missions, Unit 907 is finally granted a much-needed break. And what better place to spend time off than at a distant resort where they can lounge in their bathing suits 24-7? Against all odds, the trip is going according to plan...until Iska bumps into a certain witch who instantly reminds him of Alice. In fact, it feels all too familiar when she demands he come to Nebulis-for reasons she simply cannot reveal. And she isn't the only one with a hidden motive: Alice has arrived to investigate why her sister has been spying on Iska...for months.