Disappointing, really. Honestly, I don't understand people giving this anime such a high rating. This is a clear example of a show that has great ideas behind it but awful execution.
Yet again, as it is typical in so many bad anime, the protagonist is excruciatingly dumb and slow, to a ridiculous extent; he's no doubt the worst character. I gave the show a chance and watched the 24 episodes expecting him to wise up a little bit, but the guy is basically an annoying bag of potatoes ready to be beaten up and cry at every step while making terrible decisions. One would think that knowing how things unfold and having such terrible experiences in life he'd try to get a few steps ahead of everyone else, but instead he always finds himself in the middle of trouble without a plan.
We are watching literal 14-16yo kids beating each other up almost to death, for no reason at all. They call themselves a gang of delinquents, yet they don't do any kind of illegal activities, other than riding motorcycles while being minors, and fighting. The show tries to appear mature, but it comes off as edgy and cringe, instead. Also, the fighting scenes are really bad.
It's a shame, because the idea of a guy who can time-travel and has to involve himself in street gangs to save his girlfriend and friends is very promising, but it's full of inconsistencies and plot holes, things that are never addressed and are of vital importance to understand why things are happening in the first place.
There's definitely worse shows out there, and this one is quite entertaining if you turn off your brain; don't expect anything smart to come out of any of the characters, specially the protagonist.
6.5/10.