|⚠️|| Spoiler Warning!
Raku and Chitoge have a unique relationship because they were forced into becoming fake lovers by their fathers. On her first day at her new school, Chitoge accidentally knees Raku to the ground, which results in Raku getting mad at her. This is where his nickname of "Gorilla" for her comes from. While they fought early in the series, Raku was able to relate to her. They both come from gang-related backgrounds, and as a consequence they both had trouble making friends because other students were too intimidated to talk to them. When Raku sees her having a hard time talking to people he gives her advice and information on the other students so she'll have an easier time talking to them. Although they still fight, their relationship gradually improves as they spend more time together. Due to Raku's kindness, Chitoge's feelings for him have steadily grown stronger, and Raku's feelings for her are slowly growing, as it is shown in Chapter 178. When Raku was about to tell Yui who is the person he likes, Chitoge was the one who appeared on his mind, instead of Onodera, making him feel confused about his own feelings. When Marika was about to leave to America, she asks Raku what he really feels toward Chitoge. Although he was still confused about it, Marika said he has fallen in love with both Kosaki and Chitoge and that she wants him to be able to find out himself who he wants be with before she returns in two years. As of Chapter 199, Raku feels somewhat different toward his feelings for Chitoge. He gets a slightly different ease from Chitoge unlike Kosaki, Marika, and Yui. This causes Raku to realize that he is in love with Chitoge. In Chapter 227 Chitoge and Raku confess their feelings for one another and reconcile through a loving hug. Despite finally finding out their feelings for each other, the two are seperated for several years due to Chitoge departing from Japan in order to join a special person who could guide her to a career she wants. After several years past, Raku calls several of his friends about recieving invitations for his and Chitoge's upcoming wedding. He later reunites with Chitoge at the promise place to make a special promise to each other similarly to the original promise. He then proposes to Chitoge for marriage in which she happily agrees with. As Raku prepares to leave, Chitoge stops him to remind him that they should kiss. The two are nervous at first because they are both each other's first kisses; but in the end the two share their first kiss as a couple. Years later, they get married and they are shown to have son together; signifying that their connection and love for each other is very strong.
Raku and Chitoge's son, having the blonde hair inherited by his mother, but his facial features are very similar to Raku's. He's seen at the bonus/omake manga, and is a student at Bonyari High-school. Same as his father, he seems to be always 'protected' by his clan members.
Raku met Kosaki when they were children and at Chapter 221, she was revealed to be the promised girl. They met again when they were both in middle school. Raku considers her to be his ideal woman and is in love with her. While Kosaki is in love with Raku as well, she is too shy to confess to him. Both of them are completely unaware that the feelings they hold for each other are mutual. Kosaki loves Raku because he is kind and caring. Like the other girls who like him, she can be jealous of him spending time with other girls. However, her jealousy never extends to the point of bloodlust like Marika or Chitoge. She often wonders whether Raku and Chitoge's "fake relationship" is actually developing into something more special. Both she and Raku become embarrassed when they say each other's first names, and they quickly revert to what they call each other regularly. Raku wants to spend more time with her but usually cannot because he is either under watch by Claude, Chitoge's overprotective bodyguard, or has to maintain the illusion that he and Chitoge are dating, but when he is given the chance he will take opportunities to go shopping with her or help her at her parents' Japanese sweets shop. Kosaki's best friend Ruri Miyamoto, who is aware of the situation, consistently tries to put them into situations that will force them to admit their feelings for each other. These situations normally fail for random reasons.
It is later revealed that Kosaki is the promised girl. In Chapter 225, Kosaki confesses her love to Raku. Raku earned a flashback of all the things Kosaki did for him and started crying. Kosaki asks him why he's crying which he doesn't know the answer to, and both of them start crying. In the next chapter, Raku also says that he likes Kosaki as well, ever since in middle school. She understands however, that someone else is already in his heart. Kosaki gives her key to Raku as he takes it and goes away, thanking Kosaki for what she has done. Ruri then found Kosaki standing all on her own. Kosaki is confused why she isn't crying a lot and she couldn't understand her feelings. She makes a rather happy face as she asks Ruri what kind of face she's making which Ruri simply replies that she looks awful. Raku, who was on his way to find Chitoge, stops and puts Kosaki's key into his pendant. He opens it to find a letter from when he and Kosaki were younger. He finds two rings as well. Kosaki asks at the end of her letter if Raku still likes her, even now. Raku drops onto the ground and tells himself that they've liked each other all this time but they ended up knowing a little too late.
Raku and Tsugumi have a weird relationship. Tsugumi likes Raku, but this fact is unknown to anyone, even herself, and blushes whenever she's around him. One instance of this was when she and Raku were handcuffed together with "explosive rigged" handcuffs that explode when the handcuffed person's heart rate went up. Another time is when Raku compliments her, and she blushes uncontrollably. There are few times where Tsugumi thinks that she would become a mistress of Raku and gets nervous when Chitoge leaves her and Raku alone. Paula McCoy constantly tries to help Seishirō confess to Raku, however it normally doesn't end too well for Raku. Raku respects Tsugumi and is willing to do things for her as friends.
Ruri is the one who is always trying to bring Raku and Kosaki together and a very scary woman(sometimes). After Chitoge tells Kosaki and Ruri that she really isn't dating Raku, Ruri starts to put a lot of effort into getting Kosaki and Raku together. Her relationship with Raku seems to vary; she is sometimes on good terms with him, but when he misses an extremely obvious clue to Kosaki's feelings towards him, she gives him a piercing glare which confuses and scares him.
Raku met Marika when they were young children, and is she is one of the possible "promise girls". She is also Raku's fiancée. When Marika was young, she spoke in the Kansai dialect of Japanese, and had extremely poor health. Due to her health, she never had the chance to play with other children. One summer 10 years prior to the series, her father took her to a sanitarium in the mountains. There, she met Raku while he was climbing up a tree. Since she couldn't come outside to play, he came inside to play with her, bringing her all sorts of souvenirs he found in the mountains. His kindness made her fall in love with him. Her father took notice of this, and asked her if she wanted to marry him, which she did. Both Raku's and Marika's fathers made the engagement official shortly afterward. Marika is completely devoted to Raku, and is willing to change for him in any way. She addresses him as "Raku-sama", and has taken drastic measures to make herself the perfect wife for him. These measures included learning to speak standard Japanese, growing her hair long, and learning how to cook. While Raku is impressed with everything she has done, he is frightened by her obsession with him. When Honda warns Raku that Marika may not have much time left, Raku wonders and worries about her health and tries to make her happy.
Yui appeared in chapter 118 and she an Raku share a sibling-like relationship considering the two have been accauinted to each other since their respective childhood. He affectionately calls her 'Née-chan' at least when they are home or alone. He cares her like an older sister where she also cares him like a younger brother. After losing her parents and gaining the 'Char Siu' title Yui came back Japan only to be reunited with Raku. Yui clearly stated to Chitoge and others that she is in love with Raku. So she spends to spoil and tease Raku. She doesn't mind being Raku's bride and sees as an option for Raku if his career doesn't succeed.
After being pressured by Ie and Marika, she confessed her love to Raku but got turned down when he told her that he likes her as an older sister and also because he likes someone else. After that they maintained their sibling-like relationship and support his romance.
Raku considers Shū one of his first and dearest of friends. When they were children, Raku was isolated in his school because of his yakuza family. Shū was the only one in the class to befriend him back then, and they have been best friends ever since. In high school, Shū was also the first person to discover Raku and Chitoge's fake relationship. Despite being friends, Shū frequently plays pranks on Raku that normally put him in bad situations. Shū also constantly helps Raku out by trying to get him with Onodera as well as Chitoge, understanding his friend's feelings and giving him support. They are able to talk about anything together, and Shū was able to tell Raku about his feelings towards their teacher. Raku is also the only character in the series to see whenever Shu is hiding behind his smile or not. When Shū was heartbroken after learning that she was getting married and retiring, it was Raku who came up to comfort his friend. Indeed, their bonding is so strong, that Raku once even defended his friend when Ruri Miyamoto made a blatant analysis of him.
Raku is the heir to the Shūi Clan and therefore is praised by all of the Yakuza gang. The Yakuza gang truly care for Raku and are very protective of him whenever he deals with any trouble. The Yakuzas have shown to also be the only people to have given Raku chocolates on Valentine's Day before he met Chitoge and the rest of the girls. The gang truly supports Raku's relationship with Chitoge and tries not to cause any trouble between them when they're on a date. They watch their dates sometimes but don't know that their relationship is fake.
Raku and Haru met with rocky introductions. Apart hearing from vile rumors of Raku being a dangerous person rooted from the Yakuza, Haru also misunderstood him as a disloyal lover to her partner and had him caught repeating glimpses wearing only her undergarments. Haru loathed Raku for these reasons but the latter does not share the same sentiment as he tries his best to clear up any misunderstandings she has of him. While his first attempts didn't convince her, surely enough, Raku and Haru slowly began to open with each other due to their common interests, particularly towards sweets and cooking, however Haru would still act cautious around Raku from time to time. Eventually - after learning about the truth of Raku and Chitoge's false relationship - Haru came to acknowledge Raku as trustworthy and generous, qualities that made her fall in love with him. Nonetheless, Raku continued to act in good will towards Haru, despite her being anxious in regards to her feelings for him.
Claude dislikes Raku. He is seen calling Raku a brat most of the time, only calling him by his name when talking about him as a target. Claude suspects that Raku isn't really after Chitoge, therefore, his relationship with Raku seems to be on very bad terms. Claude is constantly stalking Raku and Chitoge to see what they are really up to, looking for anything that seems to him to be a sign that they aren't really in love with each other.In chapter 219 he tries to intervene Raku of chasing Chitoge and tells Raku that he knew all along that they weren't a couple.