|Uniform | Link Coord | Chibi|
|Affiliations||Star Harmony Academy|
|Debut in DCD game||Part 1|
|Debut in anime||Hello Friends|
Aine Yūki (
Aine has long, curled, bubble-gum pink hair that fades into a peach ombre at the tips. She has straight bangs in the former color, and is usually seen wearing a blue, rounded bow on her hair. She has short curled locks that she wears over her shoulders, beneath her ears. Her eyes are large and a bright red and orange, with brilliant golden-yellow specks.
Aine has an innate talent for making friends. It's reflected in her catchphrase: 'I'll make a million friends!'. She is a cute idol and has a great talent for making new friends and because of her talent, she befriended Mio and they became best friends.
- Mio Minato - Aine met Mio or the first time when she went to deliver Mio's tomato basil cheese sandwich from Penguin Cafe. After a few incidents caused Mio to visit Penguin Cafe and Aine gets Mio to play with her and Aine's little friends. Mio states that she was in a pinch, and without thinking Aine readily agrees to help, not knowing that MIo requires her to do Aikatsu with her. They form a Friends! unit named Pure Palette and aim to become Diamond Friends.
- Chiharu Hachiya - Chiharu is the designer for Aine's desired brand Sugar Melody. When Aine saw Chiharu's design for the Little Charmant Coord, she couldn't help but get Chiharu to make that an actual coord for Chiharu's dream brand.
- Nene Yūki - Nene Yūki is Aine's mother
- Masamune Yūki - Masamune Yūki is Aine's father
- Yoshitsune Yūki - Yoshitsune Yūki is Aine's brother
- Kazune Yūki - Kazune Yūki is also Aine's brother
- Suzune Yūki - Suzune Yūki is Aine's sister
- Momone Yūki - Momone Yūki is also Aine's sister
- Yūki (友希)
- While Yū (友) is the kanji for 'friend' and ki (希) is the kanji for 'courage', the surname is also a pun on the word 'courage' (勇気), also pronounced yūki. It's a pun on an actual Japanese surname, written using kanji 結城, as well.
- Aine (あいね)
- Due to the name being written in hiragana, it does not have one specific meaning. The most common rendition of this name is written using the kanji 愛音, meaning 'love' and 'sound' respectively.
- Aine's ribbon is blue, which is similar to the theme color of her friends partner Mio Minato
- Aine's favorite food is the 'Tomato Basil Cheese Sandwich' from her family's cafe, the Penguin Cafe
- She loves animals and also considers them her friends
- When asked what her goal was, Aine states that "It is to make a million friends". This implies that Aine has not yet thought of an actual ambition in life.
- Whether it's a friend she just made or a long time best friend, Aine is always ready to put aside her priorities for them.
- Aine loves to greet people wherever she goes, whether she knows the people or not.
- Aine loves her family very much.
- Aine is the tenth character in the entire franchise to have dual-colored hair, following Sora Kazesawa, Mikuru Natsuki, Rin Kurosawa and Nina Dōjima from the original Aikatsu! series, as well as Tsubasa Kisaragi, Yozora Kasumi, Lily Shirogane, Elza Forte, Yume Nijino and Kirara Hanazono from Aikatsu Stars!, followed by Mio Minato.
- Following Sora, Nina, Yume, Yozora, and Lily, she's the sixth character in the franchise with gradient hair.
- Aine has the similar eye color to Elza Forte and Yume Nijino from Aikatsu Stars.
- Both characters also have pink hair, although Aine's is lighter in color, shorter, and has a gradient.
- Aine's appearance resembles Orine Aida from AKB0048.
- Their names both end with the syllable ne as well.
- They both have pink, fluffy hair, although Aine's has a gradient.
- Both Aine and Mio's name can be alternately written using kanji 愛音.
- She shares her surname with Aikatsu Stars!' Subaru, however with different kanji.
- Following Mikuru, Yozora, Asahi, Mahiru, and Aria, she's the sixth character in the franchise whose surname can also be used as a first name, followed by Mio, Maika, Ema, and Mirai.
- Aine's full name has the exact same number of syllables as Maika's full name.
- Aine bears many similarities and contrasts to the other protagonists, Ichigo Hoshimiya, Akari Ōzora and Yume Nijino
- Aine is the fourth main character to have a bow-type accessory on her head.
- Aine is, however, the first main character to have a bow that isn't in a shade of pink/red. (Her bow is blue).
- Just like Ichigo and Yume, Aine performed a Special Appeal on her debut performance.
- Following Ichigo, Aine is the second protagonist to actually be unaware of Aikatsu before a series of events leading up to her debut.
- Aine is the only main protagonist to not have a word related to the sky in her full name.
- Aine is also the first main protagonist whose debut is a duet rather than a solo.
- Aine is the first main protagonist to share her status of the lead character with another character (specifically, Mio Minato.
- The debut of Aine's brand Sugar Melody officially brought back the Top Designer system, which was abandoned in Aikatsu Stars
- The relationship between Aine and her designer Chiharu Hachiya resembles that of Akari Ōzora and Sena Tsubasa. it also resembles the designer-muse relationship between Yume Nijino and Koharu Nanakura.
- Aine is the second main protagonist to have the word 'Sugar' in their primary brand.
- Aine is also the first main protagonist to make her debut wearing a Rare coord rather than the usual Normal Coord.
- Just like Ichigo and Yume, Aine's family runs a food store.
- Aine's food store is the second one to actually bear importance to the plot, following Nandemo Bento
- Aine is the second main character to have gradient hair, following Yume Nijino.
- Coincidentally, the two of them share their eye color.
- Main article: Aine Yūki/Image gallery