The characters of Kimi ga Ita Kisetsu, including the additional cast from the remake.
Protagonist
The protagonist and an aspiring photographer under the wing of Mitsuko Kouzuki, a famous model and professional photographer. As he prepares to graduate from highschool in order to pursue his career, he also considers setting up with a girlfriend, be it among his four Childhood Friends among the Isumi sister, or someone else entirely.
- Chick Magnet: Masaki has no more than eight different women attracted to him, with the exception of Mitsuko who slept with him as a whim, without much romance.
- The Ditherer: Depending on the route, he can be struck with a difficult choice regarding his love interest, upon leaving Japan to work in New York at the end of the first part.
- Akira: He hesitates for a long time until becoming an item with her, because of her lack of maturity and refusal to leave him when he has to go to New York. He eventually goes after she's talked down by Mitsuko and realizes how it is important for him.
- Marika: Being the closest childhood friend of Masaki as she's in the same class as him, he doesn't know how to treat their relationship as a platonic or romantic one. With some advice from Kenzou, the rest of the sisters and his friends from highschool, he eventually confesses to Marika, who accepts his departure to New York.
- Inverted with Yayoi: She actively wants to break off her relationship with Masaki, when she sees how it makes him hesitate to pursue a professional career for an average woman like her. Eventually, she accepts to maintain their relationship upon seeing his willingness to stay with her.
- Averted with Michiru, who quickly accepts the situation and encourages him to study abroad.
- Pretty Boy: He's quite good looking, which would easily explain his large number of admirers.
The Isumi Sisters
Four sisters and the collective Childhood Friends of Masaki.
- Childhood Friend Romance: All of them have known Masaki since they were kids, and all of them have a chance to end up in a relationship with him.
- Four-Temperament Ensemble: Akira is the passionate and short-tempered Choleric, Marika and the calm and friendly Phlegmatic, Michiru is the methodical and brooding Melancholic, and Yayoi is the cheerful is easy-going Sanguine.
- Sibling Rivalry: Michiru and Yayoi are often at odds with each other due to their status as the "smartest Isumi", though it's mostly one-sided on Michiru's part, as revealed in Yayoi's route.
- Sibling Triangle: They unfortunately happen to fall for the same guy they know since childhood. However, regardless of Masaki's choice, they don't mind if he chooses one over the others or even anyone else, with the exception of Akira.
- Voiced by: Emi Motoi (Full Voice Edition), Yoshino Nanjo (remake)
The youngest of the four sisters, Akira has a boyish and naive personality, due to being raised by her older sister Yayoi, who spoiled her quite a bit. As a result, she's quite short-tempered and tends to say what she thinks without hesitation, often causing embarassment or teasing from others, with her main target being Masaki, who often trades barbs with her. As the youngest Isumi, she's is at a difficult age when she doesn't mind being treated as the youngest sister, but she also wants to be treated like a woman and be perceived as "mature".
- Annoying Younger Sibling: She's the youngest Isumi and kind of a brat to begin with.
- The Baby of the Bunch: Youngest of the Isumis, which has led to Yayoi spoiling her quite a bit as a child.
- Bratty Teenage Daughter: Rather immature and spoiled.
- Brutal Honesty: Akira's rather blunt and says what she wants to say without thinking about how others may take it.
- Clingy Jealous Girl: Is rather clingy to Masaki and her sisters.
- Mature Younger Sibling: She wants to be this, but is too immature and short-tempered to fit this at first.
- Took a Level in Kindness: She becomes much nicer over the course of the story.
- Voiced by: Megumi Kubota (Chronicles: Inheritance), Yukari Minegishi (remake)
The second youngest of the four sisters.
- A-Cup Angst: She's bothered by the fact that she's not well-endowed like her sisters are. It's a sign that she's adopted.
- High-School Sweethearts: Among her sisters, she's the closest to Masaki since they share the same age and same class in highschool.
- Oblivious Adoption: She's not part of the Isumi family by blood, but only Yayoi and Michiru are privy to this information.
- Tsundere: Of the Sweet variant, being a mostly nice girl in public but more vocal and passionnate when in presence of Masaki.
- Voiced by: Umi Tenjin (Full Voice Edition), Kumiko Watanabe (remake)
The second oldest of the four sisters.
- Voiced by: Sayoko Inoue (Full Voice Edition), Ichigo Sasuga (remake)
The oldest of the four sisters.
- Team Mom: Due to being the oldest of the Isumi sisters, she acts as a motherly figure.
Kouzuki's studio and associates
- Voiced by: Nao Fujishiro (Full Voice Edition), Kotomi Iwamura (remake)
A famous model and photographer who takes Masaki has her apprentice.
Mitsuko's first apprentice in photography. Elder sister of Shinji Taira, Takayuki's best friend in Rumbling Hearts.
- Does Not Like Men: Her dislike of the opposite gender is very pronounced.
A freelance photographer who sometimes assists Mitsuko.
A girl who becomes Mitsuko's apprentice with some help from Masaki.
- Voiced by: Mariya Kurata (remake)
Akira's classmate who also works as a model.
- Canon Foreigner: She was added in the remake.
- Voiced by: Yoshihisa Kawahara
A world-renowned cameraman.
- Affectionate Nickname: Akira refers to him as "Hel-chan."
Masaki's friends
- Voiced by: Kouji Seki (remake)
- Voiced by: Miu Yuzuhara (remake)
- Adaptational Heroism: The Remake turns her from the rapist Psycho Lesbian Stalker with a Crush she was in the original into one of Marika and Masaki's best friends and staunchest supporters of the two's relationship.
Hakuryo High School
- Voiced by: Yuu Asakawa (remake)
- Voiced by: Shizuka Itō (remake)
- Voiced by: Emi Motoi (remake)
- Voiced by: Miki Inoue
Other friends and relatives
- Voiced by: Makoto Aoki
- Voiced by: Sahomi Koyama
- Voiced by: Ryo Sugisaki
- Voiced by: Masato Nishino
