| Isumi Akira伊隅 あきらO | |
| Measurements | Height: 155cm, Weight: 43kg, Bust-Waist-Hips: 86-54-82cm |
| Birthday | 14 August |
| Hair | Orange, Short, Thick Eyebrows |
| Eyes | Amber |
| Role | Childhood Friend |
| Visual novels | Main character - Kimi ga Ita Kisetsu ~Primary~ |
| Voiced by | Murai Shizuyo (Full Voice Edition) |
| Isumi Akira伊隅 あきら | |
| Hair | Antenna, Orange, Short, Thick Eyebrows |
| Eyes | Amber |
| Role | Younger Sister |
| Visual novels | Main character - Age Maniax ~Isumi Yon Shimai Saigo no Hi~ |
| Voiced by | Murai Shizuyo |
| Isumi Akira伊隅 あきら | |
| Measurements | Bust-Waist-Hips: 86-54-82cm |
| Birthday | 14 August |
| Hair | Short |
| Visual novels | Main character - Kimi ga Ita Kisetsu |
| Voiced by | Moriyasu Shiho |
| Isumi Akira伊隅 あきら | |
| Birthday | 14 August |
| Hair | Blond, Short |
| Eyes | Amber |
| Body | Pale |
| Clothes | Military Uniform, Pressure Suit |
| Personality | Boku |
| Role | Mecha Pilot, Soldier, Younger Sister |
| Engages in | Fighting |
| Visual novels | Protagonist - Muv-Luv Alternative Chronicles: Keishou Protagonist - Ayu Mayu Alternative |
| Voiced by | Nogami Nana |