Sakuta doesn’t wake up at 6 in the morning, because he never slept in the first place, while Mai sleeps soundly. It starts a string of days Sakuta doesn’t sleep, because as he soon learns upon returning to school, everyone there has forgotten her except his sciency friend Futaba and himself—neither of whom got any sleep last night.
It isn’t murder by Freddy in his nightmares Sakuta fears, but the prospect of forgetting Mai. So he stays up, under the pretense of cramming for exams. The next day, Futaba has slept, and forgets Mai, all but making it official. The bags under his eyes grow larger and darker as he pops stims, chugs “Blue Bull”, but Mai picks up on what’s going on.
One night, during an ostensible study session, Mai slips sleeping pills in his drink, and then strokes his head as he slowly, gradually loses consciousness, tears forming in her eyes as she comes to terms with the fact he may not remember her when he wakes up.
That brings us to the opening moments of the first episode, when Sakuta finds the notebook painstakingly detailing his past self’s experiences with Mai. But when he inspects the book, all of the instances of Mai’s name appear blank, leading him to believe it’s a notebook full of wishful thinking.
While the notebook alone fails to jog his memory, it paves the first stone. He gets another when Futaba shows him the notes her past self wrote to herself, surmising that the collective effort of the school, and indeed the rest of the world, to utterly fail to confirm Mai’s existence, could possibly be overridden by a sufficiently powerful confirmation of her existence…i.e., a confession of love.
The final stimulus that brings the memories of Mai rushing back, like water from an unclogged faucet, is a question in the exam that deals with the characters for “security” and “guarantee”; he remembers Mai’s finger pointing them out, and from them on, he knows what he needs to do…and that is to make a complete and utter fool of himself, by running out into the schoolyard and screaming at the top of his lungs that he loves Sakurajima Mai.
He yells himself hoarse, but it has an effect: the other students begin to remember Mai. Then Mai herself appears to share in the humiliation, but also to slap Sakuta for breaking his promise never to forget her, which he definitely did, if only briefly.
If the school was a box and Mai the cat, Sakuta’s bold actions broke the logical stalemate, declaring once and for all that yes, Sakurajima Mai exists, and he loves her. The “atmosphere” of unconscious ignorance of the collective student body was overcome, and thus the “world regained” Mai. She insists Sakuta continue to tell her he loves her as often as possible so that she knows he’s sincere.
From the emotional lows of Mai willingly saying goodbye to the exhausted Sakuta to the highs of him remembering her again their reunion in the yard, this was a roller coaster of an episode; Bunny Girl Senpai’s best outing yet. Was his public outburst corny? You betcha…but that’s the point!
In order to “bring her back”, he had to step out of the flow and do something no one else did. A stern talking-to from the faculty is well worth it, because Mai will be getting one right beside him. So far BGS is smart, clever, mature, and engaging romantic comedy done right.