If you're looking for manga similar to K, you might like these titles.
One day, the colossal tower, "Babel" suddenly appeared in the city of Tokyo. High school student Taiga holds the belief "not standing out is the best." While he dreams of chasing after his sister from the self-defense forces who went missing inside Babel, his daily life still continues to be boring, and the same as usual. However, on one certain day, the "time to fight" finally confronts Taiga! A new era filled with a battle of "superpowers" and an "unprecedented" tale of survival, begins now!
Tokiwa Kanenari likes to masquerade as a substitute science teacher, but he's actually in the business of dealing with the spirit world. And there are spirits in all sorts of things around him, from amber necklaces to unfinished paintings and even abandoned satellites.
Seri, a somewhat directionally challenged girl, went to Umeda for a job interview. Finding herself completely lost, she stumbles across a slightly opened door and decides to try her luck. She takes the stairs behind the door, emerging on a peculiar street half an hour later. Unknown to Seri, she has just mistakenly entered a place far more dangerous than she could ever imagine.
In the devastated city of Kyouto, color-coded gangs battle it out over the right to rule the city. A young man on a search for the brother who disappeared from his life three years ago becomes involved in this conflict.
The novel shows the events following a mysterious death in Morioh, alternating between the perspectives of Koichi Hirose, Chiho Futaba and Takuma Hasumi, two original characters and the protagonists of the novel. Hasumi's Stand is called The Book and possesses the power to record everything he sees or feels into a small, leather-bound book.
Three students are living fairly normal lives when, one day, they are overcome with intense stomach pain and a star symbol appears like a tattoo on their skin. With the symbol came supernatural powers, as well as enemies coming to kill them. As more and more people develop similar supernatural powers, it starts to turn into a Battle Royalesque bloody playground, only with an entire city as the setting and many innocents caught in the crossfire.
Nanaki survives a car accident to discover he is psychic. Recruited into an organization that solves cases with psychic powers, Nanaki's average life quickly turns into one of adventure and intrigue.
When he was young, Kurosu Keisuke was in a special TV program showcasing children with supernatural powers, called "Esper Shounen". Seven years after the termination of the program, a murderer appears to be targeting the Esper kids, whom he/she considers to be monsters. Will Keisuke and his old friends be able to discover the murderer and avoid becoming the next victims?!
Fujiwara Sunao is a rather unusual young lady. Not only does she prefer to wear her hair short and dress like a boy, but she also possesses the power to control water! One might think Fujiwara would be an odd fit at her school, but strangely, she's not. Between the destructive and demented school president, the kooky and somewhat stalker-like school nurse, and the obsessed underclassman who wants to be her apprentice, Fujiwara may be the sanest person at the school--which is a big help considering she may be asked to save it!
Mikado Ryuugamine is just trying to pass his second year of high school peacefully, but when he gets word that someone within the Dollars gang is causing trouble, that's out the window. Everybody's in trouble: Izaya is scheming, Mikado's classmate knows his secret, and Shizuo's being targeted by a mysterious girl - just another day in Ikebukuro!