Machine-Doll wa Kizutsukanai

Both series feature a supposedly weak Male character with a troubled past, and a supernaturally strong non-human loli girl who is infatuated with said male lead. A key difference is that in "Machine Doll" they are typically fighting against other pairs, whilst in "Black Bullet" they are fighting parasitic monsters known as "Gastrea". Both also take place in alternate worlds. 

Both are mix of action and comedy. Main character has overly attached loli companion who helps him in fights and also have crush on him. 

Similarities: - Master & Partner - Partner wants to marry master - Partner are not considered to be human, but master treats them as human - Main protaganist both fights - They call out their fighting styles or spells - One Boss fight per arc type of anime  

Both shows give a familiar feeling with characters and their interactions/relationship with one another. Both MCs often are involved in political strife (due to their meddlesome tendencies of saving everyone) and their political(supervisors) figure(s) having an active role with the MC. The action combat is very similar as they both fight in pairs together using martial arts technique or unique items/skills. the MC plays as the "controller" often calling orders, while the other is "supernatural" and plays a uniqie important role. 

Both animes have master-partner relationship and the partner wants to marry the master.The partners are not considered human but the master treats them as humans,both MCs are not especially strong. 

Somehow lone main with op-fighting-loli and action and stuff. 

*Both MC has a powerful rival and also has a partner to help him in combat (their partners also has some same personality) *Great fighting scenes and great characters which are enjoyable to watch. -Story is different.  

- Both have several similar qualities such as Fighting in pairs, the art style, and the characters. - Both shows give a familiar feeling with characters and their interactions/relationship with one another. - Both MCs often are involved in political strife (due to their meddlesome tendencies of saving everyone) and their political(supervisors) figure(s) having an active role with the MC. - The action combat is very similar as they both fight in pairs together using martial arts technique or unique items/skills. the MC plays as the "controller" often calling orders, while the other is "supernatural" and plays a unique important role. - Both have a younger female protaganist that does most of the fighting. - In both, the main characters try to rise through the ranks, and become #1. - The character relationship in both are a "Master-Servant" relationships. Like between Rentarou Satomi and Enju Aihara are the same as Raishin Akabane and Yaya, and it is also same how both Rentarou and Raishin don't see there "servants" as "servants" but as actual people. read more 

Both are about humans that use magic to give and improve the power of their "servants" in tournament battles. They are both about a boy that the girls in his school team loves him but they've never confessed. A girl that have small breast and envy the other girls because they have bigger ones and his spirit or machine is always saying and doing things to make it look like something happened in night between them so other girls always get angry and call him pervert 

Characters are very similar. Everyone controls another being, a spirit in this case. The main goal is to compete in a massive tournament.  

For starters, both MC's come to a new school, and they are unusual; Kamito is a guy, Raishin is Oriental. Also, there seems to be a tournament, Wiseman's and Blade Dance. Also, the first female character he seems to have contact with is doing this for their family, and her family was once prestigious but then their name tarnished. Male MC's are doing it for a specific person, however one is trying get someone back, and another is trying to seek out revenge. Anybody that watches both can easily understand that they are similar... 

A guy with a secret past goes to a battle academy that trains in fighting with specialised beings of automatons/spirits. The specialised being of the protagonist both happens to be extremely powerful and take the form of a young girl (loli). In terms of story the plot of both anime revolves around fighting in a tournament-esque environment. 

It is very similar and I'll explain why, both have excellent Light Novels, full of mysteries and the good part are that they are not predictable. Both anime have the main characters driven by their past, where they got harsh trainament, in kamito case he was an assassin with no emotions at all, until he met Restia, while Raishin had his entire family assassinated by his older brother. Then both met an old around 40 years woman, who gave then more and more trainamente and later a chance to them remake their mistakes, in Kamito's case he became known as Ren Ashbell, the strongest Blade Dancer to date and Raishin got Yaya, the strongest Machine Doll in the world. Then later both join a sort of academy with will allow then to join a tournament and they will meet new companions and create a small Harem of sorts, but both protagonists are not interested in love and always avoid the girls cringe scenes. And lastly both have great story, battles and lastly at all, both are about people who join up with a partner non-human, a spirit in Seirei and a Machine Doll in Machine-Doll and both of the MC partners are smug loli that wants to be their bride and both does not want to get in bed with them. Go to Seirei if you want something fantasy world and a excellent novel to read on Baka-Tsuki, or go to Machine-Doll if you want one in an alternative real world, or see both like I did. read more 

Both main characters are partnered with a loyal synthetic android.  

They are not very similar. However, if loli automatons be something you wish, then drop on your seat and watch these animes! 

An Automatons always should be strengthen their bonds with by her Former Master.. And Take them out in a Battle Field.. Such Gears are amongly it's important equipment to test them on their current maneuvers.. Also Both had a Clingy Automatons who could misfortunate your life.. xD 

Similarities: -Both anime have servants who are automatons/clockworks. -Both anime contains cute servant bots. -Both anime involves machines, gears, and automatons. -Both anime contains cool MCs (by mean cool with special abilities). -Both anime contains affection toward their owners. -Both anime enters a variety of conflict, battles and action. Differences: -Clockwork Planet's servant is sharp tongued while Machine-Doll wa Kizutsukanai is pleasant. -Clockwork Planet's servant had a slender body shape while Machine-Doll wa Kizutsukanai is having a Petite Body of a Loli. -Clockwork Planet's automata/clockwork do not have a lewd side while the other does.. -Clockwork Planet involes more than one ownership of a automata/clockwork while Machine--Doll wa Kizutsukanai only owns one. -Clockwork Planet do not have magic/superpowers while Machine-Doll wa Kizutsukanai involves magic that enhances the power of their automata/clockwork. -Clockwork Planet's MC uses his hearing abilites to solve problems while the MC of Machine-Doll wa Kizutsukanai uses magic to resolve a fight. -Clockwork Planet is futuristic while Machine-Doll wa Kizutsukanai is most likely British times of industrialism.  read more 

These 2 series are really similar and the only difference is that Machine-Doll is more darker and the their world's are different in my opinion 

Seikoku no Dragonar and Machine-Doll wa Kizutsukanai have many similar tropes and they deal with controlling the dragons and puppet dolls respectively. Both of these series have similar settings with Ecchi, Harem, School Life, Fantasy elements. The school where the MCs in these shows attend have battles and competition to take part in and show off their skills. The characters are similar too in the sense that how they react towards the main male character. Eco is exactly like Yaya and Silvia looks and acts similar to Charlotte. The male MCs in both of these shows have some sort of past shrouded in mystery. 

Dragonar Academy is almost identical to The Familiar of Zero but it shares many similarities with Unbreakable Machine-Doll as well, like the European setting, the protagonist's "challenge-everyone" attitude, and the presence of similar supporting characters. So far in the first episode of Dragonar Academy there has been a mysterious lady who in the past has had something to do with his partner, and a stuck-up, tsundere noble character who's taken an immediate rivalry with the protagonist.  

Both are about a boy who is infamous at his academy. Both partners are girls compared to dragons or other monsters. Both have a blonde girl that acts bitchy at first but later acts all nice. 

Both characters had tragic past. Everyone has to work in pairs be it automatons or another person. In both cases the MC's partnership is slightly abnormal Both MC's attend a school in order to gain revenge.  

The protagonists have tragic pasts. In order to rectify past mistakes they decide to enroll in a special school. These schools host competitions based around pairs. As they progress they gain new allies and discover dark secrets. 

They are both harem animes with mechanical dolls in Machine- Doll and virtual avatars in Accel World. The opening themes and the atmospheres are really similiar. 

-Both have a school settings, however in both the main characters learn more than basic academics -Both have a mystery main villain -Drama, comedy, and romance ensue between the main characters 

Not exactly similar, but the atmosphere is very similar. In either someone comes from another country or world that eventually ends up changing the routine of those people.  

-In both, there is a master/servant pair, though the roles are reversed -In both, the other familiars are creatures not humans (/dolls) -In both, there is a mystery villain and betrayal of people you know 

Similarities: Both stories are action-packed fantasies. The shows feature strong male leads, both personality-wise and skill-wise. Deep themes touched on in both series. Both series have vague harems (not as intense as most "harem" anime). Differences: In SAO characters are stuck in a video game and mainly fight monsters, whereas in Unbreakable Machine-Doll the main character uses magic and robots/magic dolls to fight others in an academy setting. Unbreakable Machine-Doll has more comedic relief and is slightly more ecchi. 

both main character leave their homeland and leave to Europe to make them self better beacause of their Father, and each one of them spend the time with some girl , and get involve in solving the problems and mysteries , and each couple have a teacher always seeking for what they doing. and both girls are annoying and always get protected by the boy main character. specially in Gosick and not so much in machine-doll.  

Similar in that both series, the main character uses girls much more powerful than him to help achieve goals. And of cause, in both the girls are smitten with the boy, and the boy is clueless...its great! 

A duo working together, and both anime's involve synthetic humans with souls. Both animes also take a stab at comedy. 

I'm surprised nobody mentioned FSN yet. Similarities: 1. Master and Servant. 2. Servants are considered as tools, but MC treats his Servant as equal. 3. Masters must provide magic on their Servants. 4. Participated in an elimination game. 5. MCs are motivated by their dark pasts. 6. Rin = Charlotte - both are -> MC's dependable companion; considered strong in their field; possible love interest; tsundere. 7. MCs with incredible survival luck.  

A man and his odd son (in the case of FMA:B, his brother in an armor, and in the case of Unbreakable Machine-Doll, his automaton) must fight for survival with their magical powers. Both animes are also placed in an older timeline, and have good music and characters. Differences: Unbreakable Machine-Doll is a shorter ecchi, while Fullmetal Alchemist: Brotherhood is more of a violent shounen. The characters from UMD live in a dorm school, while the main brothers from FMA must get on a long trip to see if they get their real bodies back.