If you're looking for anime similar to Black Lagoon, you might like these titles. All recommendations are made by Anime-Planet users like you!
When the infected approached Rei and Takashi's school, it led to a gruesome blood bath that left the majority of students and staff dead or turned into the zombie-like monsters that have spread throughout the world. Together with a handful of other survivors, Rei and Takashi set forth to find their families in a world that is rapidly detoriating. Governments have collapsed, the killer disease is out of control, and people everywhere are trying their best to simply live through each day...
Ten years have passed since the demise of the bubble economy, a time that polarized the world into two groups of people: the rich and the poor. In the present day, Saiga Tatsumi (a former war photographer) has been hired to investigate a secret club for the rich named the Roppongi Club, but he soon discovers secrets much darker than he’d ever imagined. With the help of a exploited goddess named Kagura, Saiga now possesses the power to kill by simply taking a photograph; but can he stay alive long enough to save her from her captors?
Toudou Gakuen is no ordinary high school. There, during the Meiji Restoration, fighting masters were forced to gather from all over Japan to re-establish the martial arts. Amongst the student body is a group of immensely powerful fighters who maintain order through absolute power. This "Enforcement Group" is locked in a feud with the Jyuuuken Club over matters of love and death. Now, two newcomers have disturbed the order of this school, becoming entangled in this vicious feud. Caught between sexy babes and terrible powers, the battle to be the strongest begins!
Henrietta is a young girl who works for a "welfare group" that does the government's dirty work. Cybernetically-enhanced and specially-trained, she is one of a group of elite hit-girls, remorseless killers with no memories of their past. Jose, her partner, has taken care of her since she was brought into the organization following the murder of her family, and struggles between his affection for her, and his opposing duty to his employer. But, time is running out.. for with each bullet they fire, Henrietta and the other girls lose a little more of their humanity.
There are some semilarities, both main characters are gun experts, but in Gunslinger Girls the characters are a bit emotioneless, but still the girls still have some relations of friendship between each other, in both anime there's a lot gun action, in both they take in dirty work from the bigshots and before the main story a lot of the charcters had different lifes from the ones they have now.
Something sinister is growing in Academy City. The shadows are filled with whispers of a project to clone one of the super-powered students known as espers. High-ranking master of electricity Mikoto Misaka laughs off these stories until she comes face to face with a copy of herself. The duplicates are real, and are being mass-produced from Misaka's DNA, making each one of them a little piece of her. These clones - her sisters - are being systematically murdered in a series of experiments designed to turn a sadistic killer into the strongest esper in history. Misaka vows to save her copies and destroy the project, but this might be one fight she can't win alone.
Strange recommendation is it not? Follow along with me a second. Forget Misaka and the other girls, and forget about Rock and Revy.
The real character in both of these series are the Cities they both take place in. Academy City, the home of the Railgun and Index story is a thriving bustling metropolis with an underlying sinister nay almost evil side to it.
Black Lagoons Roanapur is a gritty, ugly place where the sinister underside and evil is clearly out in the open for all to see.
Both series revel in the characters trying to survive their day to day lives in the swirling whirlpool of their cities influence.
I can't think of two completely different series on equal footing.