One of the things Baibai needs to wrap up is the mc reason for being sent back in time or rather how. Second chance at life, but who or what did it? And to what end? What happens after he finds out the actual reason he got to where is now
I'll join the "who cares?" chorus. It's an AVN, not a sci-fi epic. It's a plot device to get someone with an adult mind in a position to talk pretty girls into bed and have another chance to appreciate the family he took for granted.
Hell - even lots of really good actual sci-fi stories never delve deeply into the hows and whys of time/universe jumps.
Erased (for me a top 10 anime) comes to mind, and it never gets explained
at all...and nobody notices because - just like TM - it's about the
story, not about the mechanics.
E.g., OMG how will the MC defeat the fire-breathing dragon in this room!?
NOT
Hey...I wonder if this room is framed with wood or steel, and is the paint on the wall latex or oil-based?
If one can't suspend disbelief to enjoy entertainment, then very little will ever be entertaining, no? Obviously there are limits, but methinks you might be wanting different things from an AVN than most.