>>280909873
It is.
Though the anime kinda worded things differently.
In the manga, Takopi's mom seems to imply the act of using the clock itself is what would wipe his memories and that his plan would be breaking the rules and that he needs to be reborn. That's when he smacks her and hops on the clock.

Though, considering she doesn't know what kill even means, I wonder if the whole reborn thing was just a reaction from her out of confusion or if even thinking of going back in time to change things is forbidden.