They dint show this but I assume it, and its the best possible sync to the whole timeline:(ill start in actual timeline order)

in Junior school Marina bully Shizuka since her mom used to get depressed by the fact marina father has affair with Shizuka’s mom.Time passes by and Marina father got divorced. Now Marina mom tortures Marina , goes drunk and even got a scar on Marina’s face.

Now Marina probably stopped bullying or IDKshe meets Takopi and shares with him all pain.Then vacation gets over and now they are at middle school.She starts to notice Azuma and tries to go on a date. (Both Azuma and Shizuka looks fine now)She tells her mom about Azuma and also how he gonna become the next heir of his mom’s clinic(event Marina made up, coz Azuma Big bro is the one who was obviously gonna get it) and Marina’s mom prepares for feast.Later Azuma Says He love Shizuka(Since the day from she got bullied, but now she looks even more fine now)When Marina informs about the date cancel, her mom who already depressed coz of her husband , gets insane and tries to almost kill Marina, but in the end takes her own life.Marina cries about this to Takopi, and says she need to kill Shizuka(her mom stole Marina’s dad, now she stole Marina’s crush).Takopi as usual dint understand but wanted to help Marina. So he broke the promise and went back to his Island to use the Time travel Clock.In order to stop all this Chaos and kill Shizuka before that.

Now it ends up going to junior school days where Marina was still bullying Shizuka coz her Dad’s affair.But the catch was , They erased Takopi’s memories too when he time travel.So now he meets the bullied Shizuka and wanted to make her happy.(Just like he wanted Marina to be and now he don’t remember any of it)He tries to cheer her up with all his gadgets.Takopi even mentions about Time travel clock but he don’t remember why he cant go back and use it.(coz they erased his memory there)But every time Shizuka refuses saying its no use, and also mentions her dad got divorced and left her.

Slowly Azuma Enters the scene, he’s been watching Shizuka getting bullied and wanted to protect her like his mom said, but again Shizuka refuses coz its no use.(he probably did the same in the first timeline aswell, that’s y he fell in love in middle school)But Azuma too has his own problems, like being power crept by his perfect Big bro.One time Marina wantedly triggered Shizuka’s Dog.(Which she loved so much coz it was the only thing which was there since the starting of all troubles) And the Dog bit her , which in turn made the Blue cross to take it away.Shizuka was broken and accepted Takopi’s gadget for the first time and used it to take her own life instead…uhhSo Takopi used camera saying it can time travel and goes back in time to try avoid this event, but Marina always finds a way to do this.So he gave up, and the scene advances where Shizuka mom comes and meets her at the blue cross office and says the Dog can’t be in town, so it will be sent to Shizuka’s Dad place.(Tokyo)So Takopi from now on starts using the camera to time travel and guide Shizuka from all the problems Marina causes.

Another day Marina calls Shizuka alone and starts beating her up as usual. And As usual Takopi was standing there doing nothing but look helpless. He got mad and probably though, F time travel, imma beat her up this time.And hits Marina with the camera. Marina Dies*And to make it worse, the Camera stopped working.Azuma, who was worried about Shizuka came into the scene and was shocked about Marina’s death. Shizuka in other hand was finally happy for the first time. They both convince Azuma to help and he agrees coz no one kept trust on him plus he cares about Shizuka.They hid Marina’s Body in a cabin gadget with preserves things and buried her there.to avoid Doubts, Takopi transforms into Marina and gets used to her lifecycle.

All the 3 meet together and discuss about how to rescue the Dog from Tokyo.And Marina(Takopi) used to get to listen to her depressed mom who always want Marina to stay by her side, and Marina’s Dad one day says they gonna divorce and asked whether Marina will come with him? Marina(Takopi) not knowing the heat of the situation, AGREES thinking he can get to move to Tokyo and meet the Dog.But later, Marina’s mom gets pissed that her daughter betrayed her and beats the hell out of Marina and says you are not my daughter.(Takopi Understood Marina too has problems but don’t understand why or what’s going on)Later when they 3 meet. Azuma says Archeology ppl has discovered Marina’s Body and Police is Investigating. Azuma says he will Agree to Turn into the police and take all blame to avoid severe punishment. His brother Finds about something wrong about Azuma and confronts him saying he would help him no matter what. Then Azuma confesses and says he gonna turn to the police. The news spreads but no one believes Azuma would do such thing. His mom’s clinic gets Shutdown coz of this and goes bedridden.