Disclaimer: this will not cover any series that I haven’t watched.
As we’ve all seen recently from a lot of seasonal and former seasonal shows that have come out, time travel has been a growing trend in what we have seen in anime. A lot of it features an adult character in their late twenties who isn’t having the time of their life and either suddenly gets the ability to travel back in time. This isn’t always the case because of things like Re:Zero, which I haven’t watched yet, and older series, but right now this seems to be the case. Time travel can be insanely confusing because changing one thing can cause ripples and change different aspects of what happens later on. It’s like dropping a stone in a body of water. The ripples may only be visible for a little while, but they continue on forever
Well, what is one way to completely explain away all the time line changes? Call everything an alternate reality. Easy, done. No need to explain what has happened when because all the changes happened. From a writing stand point, it’s also easier. Usually this involves only one use of time travel or a small amount of uses over larger periods of time.
Uses of Alternate Reality Time Travel:
Dragon Ball Z: Trunks back in time to warn the Z-Fighters about the cyborgs/androids
Orange: Naho receives a letter from her “future self” in order to change the past.
Madoka Magica: Whenever Homura goes back in time in order to reset what has happened, she creates an alternate universe.
Zipang: A modern Japanese destroyer goes back to the World War Two.
The much more complicated form of time travel is what I would call the “Twelve Monkeys” variety. I liked the movie a lot, but this is more from the tv show which I like a lot. On the tv series, people go back in time and whatever they do has a huge impact on the future they came from. It could be as small as only some people have been saved compared to nobody at all or everything has been made worse than it ever has been. You know, this is all about the ripples again.
Erased: Whatever Satoru does in his Elementary school age effects his current time line on some many levels.
Girl Who Leapt Through Time: Whatever changes Makoto does throughout her day ruins everything for her. She works hard to set everything back to normal.
The Last method of time travel that I can think of is the “this is destined to happen” one. This involves aspects of time travel that have no effect on the current time line because it was meant to happen. A very easy concept to follow compared to the last one.
The Melancholy of Haruhi Suzumiya: Discounting the obvious, (endless eight *cough*), when Adult Mikuru travels to the past to meet Kyon, nothing changes in the time line because that was meant to happen.
Steins;Gate uses a lot of methods of time travel because it calculates the world line or alternate dimensions. Sure, small changes in a time line mean that not much has changed, but you are still changing the time line we see in the show at a consistent basis. If you take away the time line measurement device, it’s easily the Twelve Monkeys time line theory. That’s the problem, alternate time lines are being made all the time. It’s a complicated kind of thing and is probably the best aspect that makes the show what it is.
Noein is another one that is hard to define because it’s even more insane then Steins;Gate. I mean seriously, time lines and alternate dimensions are played around with in this series. Alternate selfs meet each other and some and even more insanity. Still, if you can get through all that, Noein is just fantastic.