Karakuri Circus

A manga by Kazuhiro Fujita (the same guy who did Ushio and Tora), placed in relatively modern-day Japan. The manga employs an unusual "choice-based" style, where it shows the two decisions a character can make at a pivotal point in a pair of boxes, a fancy arrow pointing to the decision made. The first decision is by Narumi, a sick Kung-Fu champ who decides that his job, passing out circus flyers, is more important than helping a young boy FIND the circus. He changes his mind when a group of well-dressed thugs attempt to kidnap the boy, as he rushes to save the day (still in his bear costume for work).

Then he finds out that the men after the kid, Masaru, are not men... they're dolls. Their masters are the would-be heads of a large financial empire, of which Masaru is the heir. Rescued by a mysterious silver-haired doll user named Shirogane, Masaru goes forth the find out just why the dolls and their users are after him.

Of no relation to Karakuri Odette. Or to Karakuridouji Ultimo....although the main characters act and even look quite similar...

Tropes used in Karakuri Circus include:

Accidental Pervert: Narumi decides to go help an injured Masaru bathe. Unfortunately, Shirogane already had the same idea....
Awesome By Analysis: Masaru becomes this, hijacking the bad guys's massive battle dolls, and mimicking the exact right motions to control them - after one glimpse.
Artificial Human: Some of the puppets come off as this.
Artificial Limbs: Arlequin wields a detached left arm as a weapon. It turn's out that it's not his - his is attached to Narumi.
Badass: Narumi, Shirogane, later Masaru... the list goes on for a while.
Battle Couple: Narumi and Shirogane are leaning towards this before Narumi gets whisked away by a flood, loses his memories, and is believed dead.
Beauty Is Never Tarnished: Averted, although rarely hard. One exception would be Beast, a tiger who upon introduction kills a ton of people, the second being a woman.
Berserk Button: Hurt a kid in front of Narumi. I dare you.
- And not just him. A lot of characters have soft spots for the kids. Nori and Hiro don't much like Masaru at first (because he monopolizes Shirogane's attention) but they despise a man who tells his ex-wife to leave the kids and return to him. As both of them were at one point abandoned, this makes sense.
Big Brother Instinct: Oh yeah.
Break the Haughty: A few times, with Uncle Zenji and the like. Professor Maruki (the zoologist who discredit's Drum's tail-needle and Beast's ferocity) turns out to be not so bad after all.
Character Development: Plenty.
The Comically Serious: Narumi, much to his detriment.
Cool Big Sis: Shirogane to Masaru, and to an extent the circus brothers.
Cool Old Guy: Nakamachi. Even when offered a ton of money with no apparent strings, he still promises to repay it. He seems to have quickly learned his lesson after the disastrous theft attempt.
Crouching Moron, Hidden Badass: Guy. There's no way this is just Obfuscating Stupidity.
Deceptively-Human Robots: Some cross between this and Artificial Human.
Defrosting Ice Queen: Shirogane may be one.
Despair Event Horizon: Masaru and Shirogane cross it when Narumi dies. Narumi crosses it when he "realizes" that he let Masaru die. Or so it seems.
The Determinator: Every single protagonist.
Does This Make Me Look Fat?: Of the "how do these clothes look?" variety. Masaru freezes up entirely, even though the girls in question are not the type to get offended that way.
Dude Looks Like a Lady: Knife-Wielding Vilma. The reader isn't known about this fact until someone gives him the male pronouns.
Even the Girls Want Her: When the Nakamichi Circus is doing their park performance, Shirogane is performing as the Snake King...cue the instant squees from the girls.
Face of a Thug: Narumi, among others.
Face Palm: Seems the norm when trying to deal with Guy.
Fluffy Tamer: Taranda. Able to tame cats, dogs and her pet lion Drum.
Gentle Giant: Narumi is a massive kempoist with a rough attitude and temper - but he would never harm somebody unless they deserved it.
Heroic Sacrifice: Narumi, although it's not as bad as it looks.
High-Pressure Blood: Often.
Huge Guy, Tiny Girl: Shirogane is more average sized, but compared to Narumi...
Hypocritical Humor: Nakamachi and his boys are good at this one.
Incurable Cough of Death: The plot kicks off by explaining the bizarre circumstances around Narumi's we later find that it's a sort of curse passed on from the maker of horrible dolls, to try and bring a smile to his (fake) love's face; it makes breathing agony until he can make someone laugh. Unfortunately, Narumi is not a funny guy.
Grievous Harm With A Body Part: Shirogane's puppet, Arlequin, uses a detached left arm to fight with. this is assumed to be his, right until you see his missing arm attached to Narumi.
Happily Adopted: Hiro and Nori were presumably left behind by their parents, so the Nakamichi Circus took them in.
Infant Immortality: Played with until the French village gets attacked by the evil circus.
Jerk with a Heart of Gold: Even Jerk may be too harsh; Narumi is a little rough around the edges.
Kids Are Cruel: Poor Masaru.
- Although it's subverted after Masaru saves the bullies from a couple of bounty hunters. And when Masaru leaves and helps pay a big debt to a former bully, said bully is shocked and just wanted for the two to be friends.
Knife Nut: Vilma
Knight in Sour Armor: Narumi a bit, moreso after Guy resurrects him.
Lock and Load Montage: A quick one (only for Narumi) before he and Shirogane go on to rescue Masaru.
Made of Iron: Narumi, for one. He breaks a fricking car!
Mama Bear: Shirogane to Masaru. True, she tasked with protecting him, but that's not all of it. See Papa Wolf.
Manly Tears or Tender Tears: When listening to Masaru's sob story, Narumi turns around and pretend not to be interested...because he's on the verge of tears.
- A gangster who Masaru accidentally splashes in the public bath bursts into these when he sees Masaru's scars.

"It's hard being a kid with a cruel dad, isn't it?!" *blubbers*

The Messiah: Is Masaru even capable of hating people anymore? Sure, he gets mad, but Jesus did too. Plus he forgives a man who nearly got everyone he knew (a small group, but still) killed for the sake of money...and then saves his life. For two different men like that.
Nakama: Narumi develops both romantic and filial feelings (respectively) for Shirogane and Masaru; when the latter two take off later on, they form a similar connection with the circus men and animal tamer.
Nosebleed: Happens often.
No Sense of Humor: Narumi.
Not Distracted by the Sexy: Narumi again, when an automaton girl tries to force him to "love" her. Maybe if it was Shirogane...
Oh Crap moments, especially when Narumi realizes he's been fighting machines the whole time - this epiphany happens TWICE; Narumi STILL beats the crap out of anybody who gets in his way; when everyone realizes that there's a bomb under the mansion, along with millions of gallons of gasoline, etc; that moment when Masaru realizes that the arm around his shoulders is JUST an arm; when Masaru finds out that the entire time he's just been bait for his biological father so that the mechanical warriors can be destroyed; when Masaru's uncles sees him falling out the window and realizes the entire fortune is going with him; and finally the look on the assassin's face when Masaru LANDS in front of him. This series is RIFE with Oh Crap moments.
Panthera Awesome: Taranda's pet lion drum, and the savage tiger Beast.
Papa Wolf: Narumi to Masaru. In conjunction with Shirogane's Mama Bear, it seems like the two are his adoptive parents.
Philosopher's Stone: The Soft Stone.
Poke the Poodle: The circus owner that tries to sabotage Shirogane's group in an effort to get her working for him again. It's rather pathetic.
She's Got Legs: After going over Ushio and Tora, it definitely seems like Mr. Kazuhiro is a leg man...
Stuff Blowing Up: Does it EVER.
Sugar and Ice Personality: Shirogane seems cold and harsh at first, but she's really not.
Tear Jerker: The end of chapter 9.
- And then right again in the next chapter, when Masaru takes his shirt off. Not even going into his life story...
- Fusae....
Took a Level in Badass: MASARU. Oh my GOD, Masaru.
- And Narumi, from a weakling kid to a brawny martial artist.
Tuck and Cover: Which ends badly for Narumi - his arm is chopped off - but he survives. Loses his memory though.
When She Smiles: Implied, and occasionally shown, with Shirogane. Narumi may also fall under this, because when he relaxes his normally scary visage, he can even be handsome.
Who Wants to Live Forever?: Or at least 200 years. A particularly tragic example.
Why Don't You Just Shoot Him?: One can wonder why Masaru's siblings feel the need to send in elaborate, conspicuous, and highly destructive mechanical puppets to do a job that would be much more easily done with a sniper rifle...
Younger Than She Looks: When one meets Taranda Liselette (a brilliant animal tamer) one would assume she's around Shirogane's age...she's actually 14.