But then suddenly a lightning strike somehow producing a time slip transports her baby to the same place 1&1/2 decades before as she watches it with a horrifying glance.

Back at that time, a 4th grader named Mizuki is home alone at night after expecting to leave Japan following her dad's transfer to England, but because of criminal negligence they couldn't arrange a ticket for her.

In the end, Mizuki decides to stay in Japan, raising her future baby until she can return to her timeline and names her Mirai(Hope).

Mizuki really wants to go see Ryuchi, her childhood crush's football game tomorrow with the nearby town's school, but she can't, as at the last moment her aunt Izumi got out to be at a luncheon date of convenience.

With a few moments left for the game to begin, Mizuki gets a call from her friend duo, Tamae & Eriko, urging to visit the sports place.

As she wants to enjoy the game with her friends, she puts Mirai in a worn-out apple cart and appoints Bobby to guard duty.

But he abandons it and starts chasing another dog, which results in Mirai meeting the nervous and timid Daihike, Daisuke's little brother.

They have a scuffle, both fall down to the soccer field and both start to cry, resulting in the game getting paused and Mizuki making up an excuse as to who this baby is.

Coming home, Mizuki, after seeing a saddened aunt Izumi and a lost Bobby, who would be found three days later, starts wondering as to why Mirai seemed particularly attached to Daisuke.

So, she coaxes her superstitious aunt Izumi with several days of laundry service to being Mirai to school for a memorable musical performance.

After getting notified about a cooking event Mizuki decides to make a dish for her crush Ryuchi's mother to stand at better odds of becoming his wife.

After much practice and much hectic activity in the classroom next day, she finally does serve the dish, but the person turns out to be Daisuke's mother.

Going there they find it is actually a crazed scientist that wants to build a steam locomotive and to go to a specific date in the past, Back to the Future Part III style.

But in the momentary confusion, Mirai slips away to some high hilly place and Mizuki's locator compact disc gets lost.

Even aunt Izumi refuses to attest to that, as with this she can finally get rid of Mirai and the dog, Bobby, to prioritize her manga/artistic career, as that's later explained to Mizuki.

After getting the chance of spending two nights in a mountainous luxurious hotel free of cost, the three of them Mizuki, Mirai and Aunt Izumi leave for it via train.

It is a Baby's Day Out like plot, where Mirai, Daisuke's timid brother Daihike & the neighbour's little toddler child Julietta all roll around withiut anyone taking notice amid a hectic parade preparation going on for the town's 20th anniversary.

There Daisuke again challenges him to a competition of breath holding in the deepest part of the pool, which he wins, but then his swim trunks get entangled in something deep there, so Mario has to go save him and up there Mizuki gives him CPR to resuscitate him, thus making it her first kiss.

After an argument about how daihike got roped in this trip and why is Mario here with his sister, Mizuki and Daisuke intentionally decide to pick sides in the village battle, the resolving of which is a tradition happening for a quite a number of generations back.

She does disheartened, but after looking at Mirai's face, she decides to be thankful the Mizuki and her friends for her helping her out and as a reward takes them to the amusement park.

While there she has a thought about how the version isn't seeing her baby growing up all this time, so makes a chalk drawn charm on the board of the classroom, and then prays to the compact disc.

Then they take their notebook upon the teacher's arrival and head back home hopefully this time to complete their homework fully undeterred.

There she fiercely defends Mizuki for doing all the work & chores, taking care of the baby and visiting aunt Izumi in the hospital, even though she's only 10.

Confronted by a haughty sixth grader's intense performability, Mizuki decides to really give her best and with Daisuke as her director, helps to produce a video worth awe.

Aunt Izumi was hiding in it a 10,000 yen(70 dollars, 40 cents, according to 2024) amount of currency that was supposedly hidden in a corner by her elder sister Ruriko, Mizuki's mother.

There, Daihike tearfully utters his first word, ''Nii-san'' meaning "Brother" which softens Daisuke's temperament and they hug it out & cry.

She then discloses the reason why wanted Aunt Izumi to change her manga style is because Mirai must have a parting gift like this before she eventually goes away.

A shady guy belonging to a vulgar magazine decides to interview Mizuki and Mirai and then use this story to spin it as a terrible and preposterous deal, of a fourth grader birthing an actual baby.

The teacher parent council has decided to transfer Mizuki, unless Aunt Izumi can provide proof of her motherhood to Mirai, which she doesn't have.

The columnist deemed a fraud and everything written about her to garner more paper records, she bids goodbye to her close friends Tamae, Eriko & Daisuke.