I came into this manga expecting crazy and my expectations still got blown away. Under Ninja shows a very comedic wacky world that can instantly go from 0-100. The series provides a vibrant cast of characters which it isn't afraid to cut down on at times providing real tension for every confrontation. You get to see multiple gadgets be used for dumb combat ranging from invisible clothes that only make your torso invisible all the way to talking motorcycles and special cardboard boxes. The interactions with Kuro and other characters are funny but also sometimes drop hints of worldbuilding which you can't always be sure of theirvalidity. The mystery of figuring out what it going on mixed with intense action and dumb stupid comedy provides for interesting story telling which fits its own vibe of crazy dumb stupid fun.

This series is like a mix of Gantz and Chainsawman plus dumb stupid humor. I heavily recommend anyone check this out because this series is severely underrated for how good it is and this series manages to have one of the most insane manga read moments I've experienced in a reading session(you'll know when you get to it).