
If you're looking for manga similar to Yuubin Haitatsunin Hanaki Touko CASE Oyayubi Dorobou, you might like these titles.
One day, high-schooler Anna receives a mail from her friend who suddenly got transferred a year ago. She hopped to the bus hoping to meet the only person who can understand her, but once Anna realizes she couldn't remember her name, the bus stop and now she is stranded in a strange city resided by nobody, except the horrific monsters that would not stop hunting for flesh...
The sullied air of the world can only be cleaned by the stix, a device powered by human limbs. Tonika, a rich nobleman fell from grace when his fathers plan to overtake the government was botched. Now poor and unable to afford the limbs needed to power his stix, Tonika faces the challenge of learning how to live on the other side of the class pyramid.
At St. Lucia Academy, the body of a male teacher has been discovered in the pool. The girl who found him, Mizuho Kousaka, is a shy bullied student who seems relatively unaffected by her discovery. After all, this isn't the first time she has seen a corpse. In order to teach Mizuho to stand up for herself, a girl named Shion Sonozaki befriends her and the two become inseparable, as they both share traumatic pasts. But when another body is found, Mizuho comes under suspicion for murder.
There's been a string of mysterious deaths, where the victims are torn up for no discernible reason. One day, the situation escalates and Homura Kei's computer class of 36 people is slaughtered. Due to Kei's delinquent behavior in skipping class, she ends up as the sole survivor of the massacre. When she goes home that night, a hacker called Yuon comes to her door. He claims to have also lost someone to the mysterious murderer, and he has information that Kei does not. Apparently, someone has created a program that can affect humans through the image of a blue butterfly on a computer screen, and that someone is using the program to murder people. Kei and Yuon will have to track down the murderer, before whoever it is decides to finish them off!
Ririko lost her parents and siblings in a mysterious incident where details remain in the shadows. Before Ririko moves to her new home in Kaminoshiro, a detective gives her a letter that her father wrote before his death, which contained a card with a black and white checkered pattern on it. At her new school, Ririko becomes friends with Maya and has some interest in a male student named Shirou. She questions about the black clock tower that stands in the center of the town, but no one bothers to answer the question. Her new life in her new home seemed all as well until one day Maya calls Ririko out and takes out the same checkered card that Ririko was given to her and she summons some unknown creature! As Ririko is in confusion as to what's going on, Shirou appears and says "Not another one..." What's going on around here?
Years ago, the mermaid inhabitants of an underwater brothel were ruthlessly slaughtered for their expensive body parts. The only survivors of this massacre were three young sisters who, enraged by having witnessed their mother's murder, now lure sailors into the depths to devour them. While chasing jellyfish one day, the middle sister, Julie, is caught in a net and hauled to the surface. She manages to escape from this ordeal alive, but during her brief time on land the mermaid fell in love with a human. Can the two lovers find true happiness together, despite their conflicting backgrounds?
26 years ago, something terrible happened in a middle school’s third year classroom. A popular, talented student named Misaki suddenly died, and the ramifications of that incident have caused each third year class since then to live in fear. It is now 1998, and Kouchi Sakakibara has just transferred into the notorious classroom, curious about the mysterious secret that his peers are hiding from him. He’s drawn to one enigmatic girl named Mei Misaki, a quiet student who wears an eye patch and warns him about getting involved with her, and continues to seek her out against the pleas of his classmates. And that’s when people begin to violently die...