Shū Maiko

is a supporting character in the Nisekoi series. He is a companion and best friend of Raku, whom he has known since pre-school, and is often described as cheerful and silly, though a more serious side becomes apparent as the story progresses. Shū was the first person to find out on his own that Raku's and Chitoge's relationship was fake.

Background
Most knowledge given of Shū's background relates to his friendship with Raku; Shū and Raku have been friends ever since their pre-school years. Even though Raku was isolated in his classroom by his peers because of his association with a Yakuza family, Shū would approach him when no one else did and consult his help in class.

It is also revealed that, in 6th grade, Shū's mother was hospitalized, though medical details are unknown. During this time, he pretended to be cheerful as usual in the presence of Raku, but Raku noticed his lies beneath his fake smile.

In Yui's introduction, it is revealed that he has a sort of "master-slave" relationship with her dating back to their childhoods, but it is only briefly mentioned.

Personality
On the surface, Shū is instantly recognised as a "happy-go-lucky" type of person. He is approachable, silly, mischievous, brightly cheerful, and almost always smiling or grinning. His antics label him as the class jokester and, oftentimes, a source of regular comic relief. He expresses an obsession with cute girls and has been described as a skirt-chaser on multiple occasions; for this, some girls (such as Ruri and Tsugumi) regard him as a low-life pervert. Even though perverted, Shu is actually popular among the girls in his school, and unlike Raku, he receives love chocolates on Valentine's Day as well as a face-to-face confession from an admirer.

Shū also has a habit of meddling in other people's affairs, especially Raku's and Chitoge's fake relationship; he often tags alongside Raku and the gang in various events despite being uninvited. But even so, Shu has a healthy relationship with the girls crushing on his best-friend Raku.

Beneath the surface, Shū is actually intelligent and perceptive, often using his persona of humour to elevate this intelligence from discovery. He is very observant; he was almost immediately able to deduct the unauthentic nature of Raku's and Chitoge's "relationship" and Kosaki's crush on Raku. Shū's grades and academic standing are surprisingly high, and he was ranked 22 of his class as a first-year in high school, and he even surpassed Ruri Miyamoto's rank (23). His 1st-year homeroom teacher, Kyoko-sensei, recognizes his maturity almost immediately as far above that of his peers.

Shū is also secretive of his own feelings and hides them under a constant guise of playfulness and happiness. Though with a push from Raku, Shū is also shown to have a more serious side and that he prefers to stay optimistic and not to wallow in depression even in the face of hardships.

It should also be noted that Shū is one of the only males in the story that fully supports Raku, and not half-heartedly like Raku's father.

Relationships
"Main Idea: Relationships of Shū Maiko"

Appearance
Shū is a high schooler who is slightly above average height. He has short to medium messy dirty blonde hair and wears circular glasses. He has golden brown eyes and slightly tanned skin, similar to Raku's.

In the winter, Shū wears his school's uniform which has his brown and white slip-on shoes, black pants with a brown belt, a white long-sleeved shirt, and the school uniform jacket. The summer school uniform's only difference is the white shirt is short-sleeved and the school uniform jacket is not worn.

Although he is rarely seen with screen time outside of school, Shū usually wears casual clothing. For swimming, Shū does not wear a shirt and wears green or brown swim shorts as seen in Swimming and At the Beach. When doing outdoor activities, he is seen wearing a cloth around his head

Shū is nearly almost always seen smiling or grinning, and mostly illustrated with a cat-like smile when mischievous or pervert antics.

Abilities

 * Photography: Shū is known to have a hobby of hidden photography, which can be associated with his perverted side; many of his pictures are deemed as masterful. There are times when he uses his hobby for others; an example is when Shū took a picture of Ruri with her great-grandfather during the one time she smiled.
 * Character Analysis: Due to his mature inner personality, he is able to easily understand the situations and feelings many of the characters experience throughout the series (although, it may be noted that this may function more as a plot device).
 * Uncanny Timing: He is known for being able to enter a moment when his appearance would make the most impact, such as when he appears right as Ruri was to tell Raku that Kosaki liked him, and when he just happened to be present when Ruri called Raku so that he could join them on the trip to visit the former's great-grandfather. It is later revealed he is doing this on purpose to accomplish whatever goal he has in mind.
 * Master Manipulator/Tactician: During the marathon chapter, he is able to not only gather all the males in the class against Raku (due to their unified hatred of him) but also able to establish an elaborate and near foolproof plan to keep him from winning.

First Year Arc
Shu first appeared when Raku entered their classroom. Seeing Raku's state after getting kneed upon, he asks what happened. Raku answered that a girl kneed his face, but he did not believe him. After Kosaki Onodera puts a bandage on Raku's nose, he jokingly says, “Good for you, Raku,” which annoyed Raku.

After a few days Chitoge Kirisaki transferred to their class, he asks Raku of their relationship. He replies that they're not even good friends. Shu then mentions that Chitoge is practically famous in their class. He even says that there had been lots of questions concerning Chitoge in their class, like "Why did she transfer?".

A few days after Raku and Chitoge's date as a fake couple, before Raku was able to explain to Kosaki of what really happened, Shu interrupts them and reveals that two of their classmates saw them on a date, which caught the whole attention of the class. Raku and Chitoge then put up on a fake act (after seeing Claude and almost spilling the fact that they're a fake couple) of being chummy with each other, which the class cheered on. Shu joins in, saying that he's jealous of Raku having a girlfriend before him.

Raku then asks him if Chitoge has any friends, but he replies that Raku's the boyfriend so he should know.

Despite not being invited, he joins Raku and the others in their group study session. After asking him and Chitoge if they ever kissed, Raku drags him outside and reveals the truth. He then admits that he knew from the start.

On the day of the swim meet, after Raku saves Chitoge from drowning, Shu lies to Raku, claiming Chitoge wasn't breathing. He advises Raku that he should give her artificial respiration. After she wakes up, he laughs uncontrollably. In the end, he asks Raku, out of Kosaki and Chitoge, whose body was better and said that Chitoge was a little plump for his taste causing Raku and himself to be tossed into the pool by Chitoge.

Chitoge saved Shu when he was going to be killed by Tsugumi for behaving too chummy with her mistress by calling him a 'friend too...somewhat'.

Second Year Arc
Still as cheerful as ever, Shu was still himself.

Third Year Arc
A junior seeks the help of Ruri as she wanted to confess her feelings to Shu and believed that Shu and Ruri were very close. Possibly because of Ruri's jealousy, Ruri advises her against it but the junior adamantly did it anyway. Ruri trails the underclass woman while the latter was confessing to Shu (who turned her down) and was later to be spotted by Shu.

When Raku looks for Chitoge at the place where they met 10 years ago, Ruri asks if Shu is still hung onto Miss Kyoko. Shu replies with yes, but Ruri confesses anyway and states that she would be waiting till his leftover feelings pass and he would be ready to accept someone else, surprising Shu. After graduating they are found to either be engaged or planning to be married. Shu claimed the job of a teacher.

Trivia

 * Shu's character either did not exist or was not named in the original concept for Nisekoi. There was a character that appeared to fulfil his role as Raku's close friend, but he was never called by name and his appearance differed entirely (dark hair, no glasses).
 * His surname, Maiko is a Japanese female name.
 * Shu has had been friends with Raku since kindergarten and they have had been in the same class since.
 * Shu was said to be one of the few people other than Chitoge and Ruri to know that Tsugumi was a girl.
 * Shu, in the last parts of the manga, said that he was at 'no one's side'; saying that the love of Kosaki and Chitoge were both commendable to have lasted long and been strong respectively. This is evidenced by his choice of the girl when performing his shenanigans. He tried to get almost each girl closer to Raku without prejudice.
 * Shu turns out to be an extremely important character in the story in the end as his advice finally makes Raku realise who he truly loves.