Hase thinks he knows how to defeat his grandfather Kyozo, but it's a risky bet—one that could threaten his own life! Hearing his friend out, Yushi begins to make certain preparations... Will both of them survive this punishing battle?!

With Tashiro’s help, Yushi manages to get to the bottom of Mihara’s past, including the trauma he experienced back when he just started teaching. But what can he do now? Could it be fate that Yushi met Mihara at the same time he began his training? With countless feelings raging in his heart, Yushi takes the first step forward! Summer’s just around the corner, with more intense and fun(?!)-filled days to come!

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!

The long-awaited class trip is finally here! Yushi was a little nervous to be bunking with a group of guys he's barely spoken to, but thankfully they hit it off right away! Ski lessons, good food, snowball and pillow fights—the students cut loose and enjoy one last breather before the busy exam season begins. But amid all the fun, a series of unfortunate events befalls Chiaki-sensei... Without the apartment residents to turn to, Yushi's quick-thinking and go-getter attitude shine!

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...

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!