The world is never quite the same once we grow up. Villains and robots that once ran rampant in our imaginations are reduced to drawings in Manga, and our lives are distilled until there is little left but the daily grind; so it has been for Kenji. After a childhood of dreams he now runs his late father's liquor store and is raising his sister's child. The memories and friends from his early years bring him some happiness, but they become tainted as a string of murders find connections to his past. Kenji and his friends must now fight to save the future from their past and unravel the mystery of "Friend."
Mishima is a salary man who's constantly away from his wife and child due to his grueling, overtime-heavy job. After being stuck in the office on the eve of his son's birthday, Mishima boards the train with remorse and ponders his life. Before he can return home, however, a 7.0 earthquake strikes, crippling the train and leaving its passengers helpless. Mishima now finds himself as the appointed leader of a group of survivors who want nothing more than to stay alive. Together, they will try to make their way to the surface, but starvation, cave-ins and other fatal obstacles stand in their way...
Fifteen years ago, Garai was part of a group of delinquents who kidnapped Yuki, the young brother of a famous kabuki actor, on a remote island which housed a secret military base. Garai couldn't control his lust for the young boy's girlish looks and took advantage of him in a cave, followed by a grim discovery: everyone on the base was dead from an apparent leak of MW, a powerful neurotoxin. In the present, Yuki is alive, but exposure to the MW destroyed his conscience; he now lives a double life as both an attractive bank employee and a sadistic, brutal killer who kidnaps, rapes and destroys others for his own whims. Garai, plagued with guilt, has become a priest and tries desperately to save Yuki's soul, though often ending up in bed with him instead. Yuki's ultimate goal is to find MW once more to destroy the world; can Garai stop him in time?
Not really anything compares to 20th Century Boys, but MW is close. Both are gripping tales of terrorism, drama, and more - and are told in a very VERY similar way. Unsurprising as Urasawa seems to greatly respect Tezuka (re: Pluto). If you liked one definitely try out the other, though MW is only a fraction of 20th's awesomeness.
Kirihito Osanai is a talented doctor with a successful career and a beautiful fiancée. However, once he's sent to a remote village to investigate a rare disease known as Monmow, his life quickly changes forever. After spending time with the infected patient, Kirihito begins to show the symptoms of the deadly disease - his body physically changes to a dog-like form and he begins to crave raw meat; what awaits him is a slow and painful death. Thus begins Kirihito's nightmarish journey into the unknown. He's kidnapped, forced to perform as a circus freak and branded a deviant by everyone he comes across, while back home in Japan his ex-colleagues and fiancée search for what happened to him and uncover a conspiracy that shakes them to the core. Meanwhile, the search for the cause of the Monmow disease continues...
Ode to Kirihito and 20th aren't simialr in plot, but I definitely felt similar after reading them (NOTE: 20th is FAR better and way more epic than Ode, but Ode is also good). Call it a gut feeling, but I think you'll appreciate the similar storytelling style.
Punpun is a relatively normal elementary school student; he goes to lessons, does his homework and gets on well with his classmates. Unfortunately, it’s everyone else around him that’s bonkers! With a crowd of crazy teachers playing hide and seek or having extreme reactions to even the tiniest situation at school, his father kept at bay on domestic violence charges, and only his unemployed layabout uncle to look up to Punpun’s life is anything but simple. However, despite the mayhem surrounding him, Punpun still continues to quietly live on, contemplating his dreams, experiencing the joy and terror of falling in love, and trying to deal with his anxieties about sex, religion, and growing up.
Though not terribly similar plot-wise (20th Century Boys is an epic political thriller, whereas Oyasumi Punpun is about one guy growing up), they have their share of common elements. Both prominantly feature a bizarre suspicious cult (of Friendship or Good Vibrations), cover a fairly long timeline, and have similar elementary-school era arcs (in which a group of boys- and sometimes one girl, run around the city looking for porno magazines and breaking into abandoned "haunted" buildings, among other things).
At any rate, these are two of the best seinen manga available, so if you're into that demographic, I heartily encourage you to check both out.
In the idyllic, suburban Soil New Town, everyone's lives are picturesque, down to the mandatory perfectly-manicured flower bed in front of every house. But this peaceful façade is shattered when the well-known Suzushiro family disappears during a power outage, leaving behind nothing but a pillar of salt. Things get even weirder with the arrival of a mountain of this same salt at the local school, a crossdresser fixated on transmission towers, and threatening messages demanding that every citizen pay a portion of the Suzushiro family’s ransom. The plain and often-frazzled detective Onoda and her sexist and hygienically-challenged boss, Sergeant Yokoi, are called in from out of town to help, but it's a tough case to crack. Will they be able to get any information out of the gossiping townspeople, all of whom hate outsiders and have something to hide?
Another extremely well-plotted seinen mystery/suspense manga with lots of layers, hefty psychological drama, and some very despicable characters. 20th Century Boys is more expansive ("epic", if you will), while Soil has a strong supernatural leaning, but fans of one should definitely check out the other.