Sakuta Azusagawa meets a bunny girl in the library and, wanting to find out more about this mystery, he launches an investigation to figure out what is making her invisible to everyone.

DOUBLE TROUBLE?! ​Sakuta is eager to finally have a chance to spend time with Mai again, but instead, he's greeted by a stranger who looks just like her. Apparently, Adolescence Syndrome is paying Mai another visit and has forced her to swap bodies with Nodoka Toyohama, a flashy up-and-coming idol...who also happens to be Mai's half sister! With no resolution in sight, each sister must pretend to be the other and go about their respective lives as best they can. Trouble is, it seems like Nodoka is preoccupied with something besides walking in Mai's shoes...

SOMETIMES MORE IS JUST CRAZY!Just before summer break, Sakuta encounters Shouko Makinohara, a girl in junior high with the same name and face as his first love. Of course, that should be impossible, since she would be in college by now. Then, as if one mystery wasn't bad enough, Adolescence Syndrome strikes again. His impassive friend from the science club, Rio, discovers she has a doppelgänger. One of the Rios is forced out of her house and winds up staying at Sakuta's apartment. Definitely not the girl he expected to find himself living with...And when Mai insists she's going to sleep over, too, Sakuta's summer vacation descends into pure chaos.

Sakuta Azusagawa meets a bunny girl in the library and, wanting to find out more about this mystery, he launches an investigation to figure out what is making her invisible to everyone.

GUESS WHO’S BACK? ​After years without contact, Sakuta has received a letter from his first love, Shouko, asking to meet at Shichirigahama Beach. Of course, now that he’s in a happy relationship, he’s not quite sure how to respond...or how to explain the situation to his girlfriend, Mai. Maybe he’ll just focus on helping his panda-loving, stay-at-home sister achieve her goal of returning to school for the time being. But this is easier said than done, given that she hasn’t left the house for two whole years...

Sakuta Azusagawa meets a bunny girl in the library and, wanting to find out more about this mystery, he launches an investigation to figure out what is making her invisible to everyone.

“Today...is yesterday?” Sakuta may have cured Mai’s Adolescence Syndrome in the nick of time, but now he faces a no-less-harrowing task: convincing her to officially date him. After managing to win that round of verbal fencing, he gets some well-deserved rest...only to wake up “yesterday,” with all his progress reset. This inexplicable phenomenon seems to be caused by Tomoe Koga—the self-righteous yet self-conscious schoolgirl who offered up her own butt to be kicked after mistakenly assaulting Sakuta’s—and the only cure is to...pretend to be her boyfriend?!