Ristuka often takes photographs or "makes memories" because of his fear of forgetting people and being forgotten. Later in the series, his friend from his previous school, Osamu, states that Ritsuka used to be in a photography club in his old school, with Ritsuka usually taking pictures of people while Osamu takes pictures of flowers and plants.
Throughout the series, the story alludes to an abrupt change of personality occurring in Ritsuka two years prior to the beginning of the manga when Ritsuka was ten. It is often seen through flashbacks, when his mother beats him and denies that he is “her Ritsuka" and that he is actually "someone else in her son’s body". This is because Ritsuka lost his memory at the age of ten and cannot remember anything before that. Before the change, Ritsuka was a popular, academically average student. But after that changes he has become the opposite of his former self, which is achieving perfect marks in school and failing to get along with his classmates, often expressing that he hates various aspects in a person. In addition to this change, he claims Seimei, his beloved older brother who died before the beginning of the story, was the only one who could understand him. Because the cause of these drastic changes is still unknown, he has regular therapy sessions on Wednesdays to determine the reason.
The story begins on his first day at his new school when Ritsuka meets a mysterious man named Soubi Agatsuma for the first time. Soubi confuses him with his sudden intimacy and puzzling claims that he was Seimei's friend and Sentouki Unit. Ritsuka discovers that Seimei's imprompt will dictates that Soubi shall "become Ritsuka's" upon his death; Soubi is now Ritsuka’s '’Sentouki’’ whilst Ritsuka is now his ‘’Sacrifice’’. As Ritsuka deeply admired and idolized Seimei, the discovery that his elder brother had kept so many things from him furthered his difficulty in trusting others, particularly Soubi, and despite admiring him Ritsuka is continuously upset with Soubi’s tendency to keep various secrets.
PersonalityDespite his young age and inexperience, Ritsuka is very intelligent and approaches things with startling maturity. The circumstances of his life encourage his lack of innocence; however, there have been notable incidents that bare his still-strong naiveté, particularly in sexual love and dating. Despite this, he still has firm opinions and unrelenting ideas about those subjects. It is these opinions that clash dramatically with adults and authority figures around him, most notably Soubi. Ritsuka is a pacifist, and strongly opposes violence under any circumstance.
Love is an uncomfortable subject for Ritsuka. He is wary of compliments and affection, and early on in the series is troubled when Soubi says "I love you" frequently. Ritsuka doubts this is true and has trouble tolerating it, and because of Ritsuka's cynical reaction, Soubi stops saying it altogether after volume 2 of the manga. Still, Ritsuka's inner conflict over whether he believes what Soubi says becomes a source of great tension and bitterness in their relationship. However, as the story progresses, Ritsuka realizes how much he needs Soubi despite his rash attitude at times; when he tells Soubi to leave him alone, he is often seen staring at his cell phone waiting for a call or a text message.
To an extent, Ritsuka seems to have a certain charismatic personality that attracts easy infatuation, which can be found in his therapist, Yuiko, Seimei, and Soubi. Ritsuka's relationship with everyone develops a little more with each volume, although not much has been said or shown about Ritsuka's father and he still remains a rather unimportant figure in his life, unlike his mother and brother. Ritsuka is a very determined and pure child that is easily recognized and sometimes taunted by other Fighters and Sacrifices. He does not enjoy being the 'Master', and nor does he enjoy ordering Soubi around like a dog, no matter how much Soubi wishes it. He believes in free will and creating one’s own destiny. He also refuses to punish Soubi because of his past experiences in which he was disgusted by how he was abused by his mother.
- There are several sketches of an older Ritsuka Aoyagi that could be considered official to Loveless' canon since they were drawn by Yun Kouga, the creator of the series.
- Ritsuka suffers from a rare form of severe dissociative amnesia introduced by several traumatic life events including witnessing a murder and parental abuse.
- Ritsuka's amnesia began following the apparent death of his brother.
- There is a small possibility that individuals with this disorder can overcome the state of amnesia without losing the memories gained during the period of amnesia.
- In Volume One, Ritsuka states that he wishes to become as tall as his late brother, Seimei Aoyagi. This coincidently becomes a foreshadowing clue in the series since according to Yun Kouga's sketches, he grows to exact same height as Seimei at the age of seventeen.
- In Ritsuka's manga debut, he is seen wearing a jacket with elaborate embroidery. However, the embroidering was not present in his anime debut due to challenge of illustrating the complex patterns in each frame of Ritsuka's movement.
- In each episode/volume of the anime/manga, Ritsuka is depicted with a different injury: in one episode he has a patch on his cheek, in the following episode has a bandage on his arm, etc.
- This displays Ritsuka's regular abuse from his mother.
- In terms of numerical dating, Ritsuka's birth date forms a four-digit palindrome (12-21.)
- According to the databooks:
- His name literally means "The First Day of Summer."
- His name is taken from the lunar day "Rikka."
- Favorite foods: Soft things; everything McDonald's; convenience store rice ball lunch boxes.
- Least favorite foods: Too many to list- his diet is really unbalanced.
- Favorite colors: Blues; white.
- Hobbies: Making a record of his life; photography.