Close Friends[]
Shirayuki[]
Ryuu asked for Shirayuki as an apprentice because her hair color is similar to the flowers of Yura Shigure plant, which is his favourite plant. He asked her not to call him with any honorifics, even though he's technically her senior, because he thinks that it's weird for an adult to call a child like that. Slowly, he opens up to Shirayuki, and is more sociable with her now. Shirayuki takes care of Ryuu, like how an older sister would. Ryuu seems to be fond of Shirayuki and cares about her as he immediately tells Zen Wistaria about her crying when Shirayuki was looking through Zen's log book.
It is also shown that despite Ryuu's inability to read people's emotion, through his encounter with Shirayuki, he gradually started to be more observant especially towards Shirayuki. Ryuu managed to notice if Shirayuki was down or depressed a lot of times already. When it was Shirayuki's first time in the palace, Ryuu also checked Shirayuki's body temperature in case Shirayuki got a fever which she did on the night of that day.
However, Ryuu was also occasionally seen to be at loss of his own feelings when it comes to Shirayuki. This can be seen when he saw Shirayuki fell asleep, he admitted that he felt the need to do something but he didn't know what. In the Lyrias Arc (Chapter 87.5) after Ryuu got taller, he told Shirayuki that he was happy of the fact that Shirayuki's red hair which he liked was now at eye-level for him.
Ultimately, both Ryuu and Shirayuki enjoyed working together and are good friends.
Obi[]
Obi accompanies Shirayuki and Ryuu most of the time as Shirayuki's bodyguard. Due of this Ryuu also befriends him in time. Obi calls him "Half pint", "Little Ryuu" "Ryuu boy" (or Ryuu-bou), and sometimes let Ryuu ride on his back. When Ryuu told Obi and Shirayuki that his joints were aching, Obi was surprised. Thus, he picked him up to confirm his suspicion that Ryuu was having a growth spurt.
During Ryuu's first trip to Lyrias, he asked Shirayuki if Obi was going to come as it seemed to him that Obi always appeared when they least expected it. Obi even gave Ryuu an advice when Ryuu told him how he was worried that he doesn't look like someone who can treat other people who have illnesses or injuries. Ryuu also shared with Obi how he wanted to be and look like a dependable pharmacist.
Ryuu's willingness to consult with Obi regarding his worries shows that he deeply trusts Obi. The both of them share a mutual sibling-like bond. Ryuu was told that he resembles Obi after he got a hair cut.
Garak Gazelt[]
Garak is the Head Royal Pharmacist who took Ryuu under her care. Garak appears to be the closest person to Ryuu as she was his mentor and she took care of him. Garak and Ryuu have a teacher-student relationship, and a bond similar to familial bond, as Garak has become something of a mother figure for him. She cares about his health and growth even outside of their working relationship and has been his guardian since his arrival in Wistal. She even considers letting Ryuu meet a lot of people and gain life experience at the cost of sending away one of her most promising workers in order to give him a better chance socially later in life. She is concerned of him in a way of how a mother would be to her child. Furthermore, in Chapter 57, it was shown that Garak nearly cried when Ryuu stated his gratitude for Garak the night before he was sent to Lyrias with Shirayuki.
Kirito[]
Kirito is Ryuu's only friend who is near his own age. Kirito's personality is a polar opposite to Ryuu's as he is loud, playful, emotional and energetic while Ryuu is quiet, studious, awkward and reserved. Kirito's boldness and admiration for Ryuu's skills led to their friendship. Kirito, who is generally a sociable boy, easily befriended Ryuu who was awkward and inexperienced in socializing.
They first met when Ryuu was assigned to visit Lyrias for the first time by the Chief Pharmacist, Garak. While he was there, Ryuu was directly involved in a conflict in Lyrias regarding Olin Maris, a poisonous plant. When Kirito first met him, he couldn't believe that Ryuu was also one of the pharmacists, as he said that Ryuu was only a kid, which was something Ryuu agreed to. Kirito's friends were one of the victims during the Olin Maris incident. At that time, the adults had yet to find a cause or cure for their affliction. Therefore, Kirito seek Ryuu for help to save the other kids, believing that as the adults had failed, the children should rely on another child. After Kirito was affected by the disease as well, Ryuu was the one to treat him. After the end of the Olin Maris incident, Kirito forced Ryuu to participate in a snowball fight and invited Ryuu to play and visit again.
Ryuu cares a lot about Kirito from the early stages of their friendship and this was proved when he bought souvenirs for Kirito after Kirito asked him to bring goods from the capital. When Ryuu moved to Lyrias, both of them spent most of their free time together.
When Ryuu told Kirito he was ordered by Garak to go back to the palace in three months, Kirito was surprised and he said that he knew Ryuu would eventually return to the castle but he wasn't expecting it to be that soon.
Zen Wistaria[]
Zen is one of the people who didn't think of Ryuu as an adult but he still acknowledged Ryuu's talent as a Court Herbalist. Ryuu appeared to be comfortable around Zen as he was willing to share with Zen about his worries of not being able to read people's emotion. In Lyrias, Zen stated that he wanted to see Ryuu the most when Shirayuki asked him if he wanted to try anything in Lyrias. When Zen finally saw Ryuu after for a long time he was shocked to see how much Ryuu had grown up.