ChäoS;Child

Both have the same mystery, horror, and supernatural genre that both focuses on seemly random mysterious deaths that happens around.  

The second best in the semicolon series, from the same creators as S;G. While focus is different (S;G time travel, while C;C is one part murder mystery, one part psychological horror), both feature a group of teenage characters and a science-related mystery.  

Ah yes, my two favorite visual novels and pieces of fiction in general. If you have any interest in these 2 amazing stories i suggest checking the visual novel versions of them, because the anime adaptations dont do them justice. Umineko and Chaos;Child are thrilling murder mysteries with supernatural and horror elements. They both send really strong messages and have an amazing protagonist and cast of characters. What is real, and what is a delusion? 

Both Boogie and other and Chaos;Child have a deep story which will keep you confused for a while slowly giving away details to make sense of the whole situation. In both anime, you usually see the story from the main characters perspective where he is the least informed of the characters about what is happening and later on becomes the hero. Also, they both share the theme where the characters go a 'bit' insane because of psycological reasons. 

Chaos;Child is the thematic sequel of Chaos;Head. Both are in the series called Science Adventure, also Steins;Gate (which you probably watched), Robotics;Notes and Occultic;Nine, so go check those out too. They all happened in the same universe so the settings, the suspense feelings, the mystery solving, all that. 

Both are great examples on how to ruin an otherwise pretty good (in TPN manga's case) or outright top-tier (C;C visual novel) stories and turn them into inexplicably bad, cringe-worthy and rushed pieces of "entertainment" whose only value ends up being the decent animation. Chaos;Child anime is still way better than Promised Neverland season 2, in my humble opinion, but the letdown when compared to the source is comparable. The openings are both good, so that's that. I don't think I need to say this, none of the above applies to TPN season one at all. 

A similar mix of supernatural and mystery. I found the use of shock factor with gore to be pretty similar. slightly similar plot: a high school newspaper club is investigating a series of deaths that are occurring in a similar pattern to another series of deaths that happened 6 years prior. 

both school focused harem focused and equally horrible its hilarious as one another 

1. Both the characters go mad and lose their sanity, but later regains composure. 2. Both anime have "Holy Freakin shit!!!" Moments. 3. Both have 'Gory' and 'intense' moments. 

1 similar way of killing / dying in a horrible manner ( Gory and blood ) 2 Cute girls are murderers 3 both s are psychological horrors / supernatural 4 recalling the events of the past (when they were children) 5 characters go mad at the end 6 have a lot of intense' mooments 7 both s have teenage characters . / Both s are great. enjoy /  

1 Scientists experimented on main characters 2 both have mystery, horror, and supernatural genre 3 girls have superpowers 4 similar way of dying ( Gory and blood ) 5 recalling the events of the past (when they were children)  

- strange killings happen in Shinjuku (and in other parts of Tokyo - Inuyashiki) - psychological, action, sci-fi (or rather supernatural) - main character is investigating the strange murder series 

Both focus on a reserved cynical mc working along side his teamates to figure out a conspiracy behind the events that is going on in the story as well as its use of strange events to carry it along.