 If you liked
Narutaru: Mukuro Naru Hoshi Tama Taru Ko
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 ...then you might like
Yakusoku no Neverland
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It's clear that The Promised Neverland was inspired a lot by Narutaru. Both, first of all, contain children, with a cute artstyle dealing with many hardships, including gore. Both deal with psychology and characters. They both share the theme of children v.s adults. Both contain a lot of politics, and war themes.
While Narutaru is much darker and contains a lot of philosophy, YNN can be considered as a light version of Narutaru for younger readers, with a more understandable politics, less gore and less philosophy and psychology.