I just think about this now but looking past the humor and the hilarious moments, khr! is a dark anime isn't it? I mean, look at mukuro, he's gone past so much to the point where he wanted to dominate the mafia world, chrome that's been a subject of her parents neglect and even wishing her gone, then there's yamamoto that (in the manga) thinks about suicide (and he was just 13/14 years old!) so I think this anime is pretty dark itself though hidden (just my two cents tho lolol)
THIS ^^^^^^^^^^^^^ IS 100000000% TRUE!!!
Seriously the actual story can be so much darker than it looks at face value. I mean, we’ve got Mukuro, Ken and Chikusa were test subjects. Chrome’s own background. Gokudera’s living out on his own for however long and what he went through with that. The actual training of Dino and Tsuna at Reborn’s hands. What Skull’s invincible body means he goes through. And do people really pay attention to the teenage Varia members, and what that means for them. Lancia. The Choice Arc. The Arcobaleno.
So yes, it really is a dark story.