The character design has a huge problem
A grown-up MC would look exactly the same as he was in his high school years.
But, a high-school mob character would look like they are in their middle age.
Also, most of the characters have an extremely long neck which is kinda weird honestly.
The time travel aspect of this anime is weak. It literally took 2 minutes for the characters to figure out what triggers the time travel that they did.
Instead of spending time exploring how and why they time travel. this anime shows 0 effort in the time travel aspect.
I know this is an anime about gangsters but I just can't help but wonder if the police, teachers, and their parents exist in the first place. I think most people have been to school at some point of their life and we can all relate to gangsterism in one way or another. But this is as far as what we have seen in reality. The "gangster" student seem to do whatever they wanted, whenever they wanted
overall not a very good anime IMO, there are always much better options