Yushi departs on a journey around the world with the Bookseller, Hase and Chiaki seeing him off at the airport. Then, time passes...and as it does, Yushi, Chiaki, and the tenants at the apartment house face big crossroads in their lives!

The school cultural festival is underway! Chiaki's blindingly white school uniform wows the ladies, but Yushi and his classmates are going crazy serving as waiters in an outlandishly busy classroom cafe! And as if he wasn't harried enough, Yushi's quickly pushed over to help out with his English club's story presentation! Even worse, Hase's making his first visit to Yushi's school--all this and more in an event-packed Volume 18!

What emerges from the peculiar egg Mariko-san brought home with her, but an equally bizzare tadpole-like yokai with an arm growing out of its belly! The hatchling immediately takes a liking to Yushi, forcing him to walk a mile in a new mother's shoes! Meanwhile, the mishap also prompts Mariko-san to reveal her shocking past to Yushi, and in doing so teaches him a valuable lesson about the pursuit of happiness...

After spending New Year's in Las Vegas (and attending a rather eye-opening poolside party at a fancy mansion), Yushi is fully relaxed and ready to continue his world trip with the Bookseller. Soon they're on their way to England, and a reunion with their old friend the Antiquary. Things quickly go awry, though, thanks to a coin Yushi happened to come across-and the moment Yushi finally finds Antiquary, he's instantly whisked away to a treasure hunt in the countryside!

As Yushi recovers from his ordeal, he begins to ponder over just what his next move should be. All his former classmates are well on their way to their futures...but he's still just there, left behind. But as he talks things over with Chiaki-sensei and his pals at the apartment, an unexpected opportunity arises!

His magical cover blown, Yushi steels himself to tell Chiaki-sensei about the grimoire. Vulnerable and braced for contempt, what the tender teen hears instead is a series of surprising anecdotes … In other news, preparations for the cultural festival are underway, and Tashiro and Co. have big plans for Chiaki-sensei regarding their class' booth. Everyone's amped up to make this last school festival the best one yet. That is, until some unexpected trouble stirs in class ...