"Osananajimi" (JP) is a term used for character who is the early childhood friend of another character and grew up together. They have known each other since they were small children and have been close ever since so they are said to have a special kind of bond.
Etymology
Meaning of the Term
Osananajimi (幼なじみ) comes from "osa" (幼), meaning "childhood", and "najimi" (馴染), meaning "friend". Generally this refers to characters who have been friends since elementary school or earlier who grew up together.[2][3][4]
Localization
The term is generally localized as simply "childhood friend".
History
Official Media
The childhood friend is a very common character type in anime, manga, and video games. It is common to have at least one character who is the childhood friend of the protagonist, especially in harem anime. It is also common to sometimes see groups of three childhood friends as the main characters, which can create interesting dynamics.[1][5]
Characteristics
Osananajimi characters have known each other and been friends since they were very small children and grew up together.
Personality
It is said that because they grew up with one another they have a special kind of bond that is not found with friends made later in life.
They often play the role of always being by the protagonist's side. Since they have known each other longer than other characters, they have more information about each other's personalities and private lives, both good and bad. In some cases, the relationship between childhood friends develops into a romantic relationship.[2]
List of Characters
Gallery
 Tomo Aizawa and Junichirou Kubota from Tomo-chan Is a Girl!  Tomo Aizawa, Junichirou Kubota, and Misuzu Gundou from Tomo-chan Is a Girl!  Eren Yeager and Mikasa Ackerman from Shingeki no Kyojin |
References
- ↑ 1.0 1.1 1.2 Osananajimi ga Zettai ni Makenai Love Comedy. MyAnimeList (2022/10/07). “My childhood friend Shida Kuroha seems to have feelings for me. She lives next door, and is small and cute. With an outgoing character, she’s the caring big sister type, this being one of her greatest strengths... But, I already have my first love, the beautiful idol of our school, and the award-winning author high school girl, Kachi Shirokusa! Thinking about it rationally, I should have no chances with her, but, while walking home from school, she only talks to me, with a smile even! I might actually have a chance, don’t you think?! Or so I thought, but then I heard that Shirokusa already has a boyfriend, and my life took a turn for the worse. I want to die. Why is it not me?! Even though she was my first love... As I was drowning in despair and depression, Kuroha whispered "If it’s that tough for you, then how about we get revenge? The best revenge ever, that is~"”
- ↑ 2.0 2.1 What is Osananajimi. Pixiv Encyclopedia. “To have known and been close to each other since childhood. In creative works, they often play the role of always being by the protagonist's side. Since they have known each other longer than other characters, they have more information about each other's personalities and private lives, both good and bad. In some cases, the relationship between childhood friends develops into a romantic relationship.”
- ↑ What is Osananajimi. NicoNico Pedia. “Osananajimi are familiar faces from childhood. It is a close friend who played together in childhood. Although there is no fixed age range for calling friends osananajimi, friends from kindergarten to elementary school are likely to be called childhood friends in the future. In general, people who are called childhood friends are usually the same age or close to the same age as their friends, and friends who are much older are generally not called childhood friends. The appeal of childhood friends is their closeness to family, the special feeling of sharing past experiences and secrets, and the natural advantage of being together simply because they are childhood friends. There are several standard settings, such as they live next door and come and go through the window, they have a familial relationship, or the protagonist's parents and childhood friend are close friends. Since they have grown up influencing each other, there are many cases where their personalities are paired, such as a cheerful and caring person and a shy person, or a serious person and a good-natured person. In anime and video games, they often appear from the beginning with a good knowledge of the protagonist and his/her surroundings, so they can also serve as guides and commentators.”
- ↑ Osananajimi. AnimeNewsNetwork (2024/12/27). “A commonly-used term in romantic anime, an osananajimi is a friend from infancy, a childhood friend or old playmate with whom one shares the special and intimate understanding that (according to such stories) can only come from having known each other since earliest childhood.”
- ↑ Ore no Kanojo to Osananajimi ga Shuraba Sugiru. Square Enix (2013/01/06). “Eita enters high school aiming for the National University School of Medicine. Because of his parents' divorce—and his goal—he shuns anything to do with romance or love. One day Masuzu, the school beauty with the silver hair, who's just returned to the country, enters his life in a most unexpected way. Chiwa, his childhood friend since elementary school, will not let this go without a fight.”