Sachi Komine is a petite girl with short, roughly cut pink hair and striking deep blue eyes. She is the second shortest among the girls at Mihama Academy, only slightly taller than Makina Irisu. Her soft, rounded facial features and consistent smile give her a youthful and approachable look, often radiating an air of innocence and calm that contrasts with the more eccentric personalities around her.

At school, Sachi wears the standard Mihama Academy uniform for female students, a blue jumper over a white sailor-style blouse, paired with white stockings that are fastened with discreet straps beneath her clothing.

Outside of class, Sachi is almost always seen in her signature maid uniform, a choice she attributes to being told to wear it “whenever she can.” The outfit follows a classic design: a long-sleeved black blouse with white cuffs, a high collar, a white frilly apron layered over a calf-length black skirt, and a red ribbon tied around her neck. She also wears a traditional lace doily-style maid headdress, which remains a constant accessory regardless of outfit variations.

Despite often appearing in the same maid outfit in the visual novel, Sachi claims to own multiple functional variations of the uniform. These include a breathable version designed for comfort, a weapons-resistant variant for emergency situations, and a “dressy” edition featuring a supposedly brighter red ribbon though Yuuji Kazami humorously notes that he cannot tell the difference.

Later in the story, after overcoming her compulsion to obey orders unconditionally, Sachi begins wearing casual clothing gifted to her by Yuuji. This includes a gray, short-sleeved hoodie with pink lining and a matching pink skirt that falls just above the knees. She first wears this outfit on a beach date with Yuuji while still trying to embody the “good girl” persona, and continues to wear it frequently in her after story, symbolizing her personal growth and independence.

Sachi Komine is known for her unwavering politeness, sense of responsibility, and dedication to fulfilling any task requested of her. Her approach to daily life can be summed up in three words: “receive,” “confirm,” and “execute” a mantra she follows with near military precision. While her extreme commitment to this process can make her seem overly serious or robotic at times, it stems from her deep desire to be dependable and useful to those around her.

One of Sachi’s most endearing quirks is her love for sharks, which she identifies as her favorite animal. She even used her crafting skills to make a shark-shaped pouch, which is frequently seen carried by Michiru Matsushima. This creative touch adds a unique charm to her otherwise orderly personality.

Sachi suffers from both Obsessive-Compulsive Disorder (OCD) and Post-Traumatic Stress Disorder (PTSD), both of which are linked to a traumatic childhood accident that resulted in the death of her parents. Believing her decision to run away caused the accident, Sachi developed an overwhelming need to be a “good girl,” obeying every order given to her in hopes of atoning for her perceived wrongdoing. Any failure to comply or act accordingly triggers intense guilt and anxiety. Her trauma is further revealed through physical symptoms such as heavy breathing and nausea during flashbacks or nightmares related to the event.

Despite her emotional burdens, Sachi is kindhearted and dependable, rarely showing embarrassment even when discussing awkward or uncomfortable topics. She takes pride in her hard work and enjoys being praised, especially by Yuuji Kazami. After Yuuji’s arrival at Mihama Academy, Sachi begins to adopt new personality traits influenced by his presence. At times, she exhibits a flirtatious attitude or shifts into a cold, commanding tone reminiscent of a drill sergeant. These changes are often mirrored by Makina Irisu, who takes the role to exaggerated extremes. Michiru also notes that Sachi sings a distinct melody when in a good mood, a notable contrast from the nonsensical lyrics she picked up from Makina.

Before the accident, Sachi was energetic and proactive, often seeking praise from others. Yuuji describes her pre-accident personality as slightly tomboyish, highlighting her outgoing and competitive nature. She was highly motivated by approval, working hard to earn positive attention from both her parents and Yuuji himself. Even in her altered state, she continues to seek praise for specific actions such as winning a round of Xtreme Typos rather than general encouragement.

Sachi’s emotional development begins in earnest during the “Improvisation” chapter of the first game, where she starts to shed her rigid “good girl” persona. As she becomes more expressive, she begins to show a broader range of emotions, including occasional jealousy. Though she resumes some of her earlier proactive tendencies, she continues to perform habitual tasks out of comfort and routine, demonstrating a delicate balance between her past and present selves.

As a young child, Sachi Komine was bright, diligent, and deeply motivated by the praise she received from her parents. At age five, she excelled both at home and in school, constantly striving to please her parents by studying and helping around the house. Though her family operated a small factory, her parents made a conscious effort to spend time with her despite their busy schedules.

However, as the factory expanded and demand increased, her parents became increasingly preoccupied with work. They eventually hired a housemaid to look after Sachi, which left her feeling neglected and lonely. During this time, Sachi met Yuuji Kazami at a local playground. The two quickly formed a bond, and Sachi developed a childhood crush on him.

Shortly before her tenth birthday, Yuuji’s sister, Kazuki, went missing in an accident. This incident forced Yuuji to remain home, and he informed Sachi that they would likely not see each other again. Though saddened, Sachi promised to wait for him, no matter how long it took.

On the day of her tenth birthday, her parents’ workload had eased, and they decided to dedicate the day to Sachi as an attempt to make up for their recent emotional distance. However, still reeling from Yuuji’s departure and skeptical of her parents’ sincerity, Sachi ran away from home in frustration, thinking, “As if that’ll make up for the lost time.” She returned to the playground and waited for hours, only to be overcome with guilt, realizing her parents were likely worried and unaware of her whereabouts.

As she was about to return home, she saw her parents across the street searching for her. At that very moment, a truck driven by a drunk driver ran a red light and struck them directly in front of her. Her father was killed instantly, and her mother fell into a coma. Witnessing the traumatic event caused severe psychological damage to Sachi, resulting in Post-Traumatic Stress Disorder (PTSD) and Obsessive-Compulsive Disorder (OCD). Blaming herself for their fate, she internalized the belief that she must always be a “good girl” and obey every order, no matter how irrational or demanding.

Following the incident, Sachi transferred to a new school, where her extreme helpfulness and cheerful disposition earned her praise. However, her inability to decline requests made her vulnerable to manipulation. A delinquent student named Hitomi Nakano began exploiting Sachi’s obedience, assigning her increasingly unreasonable and labor-intensive tasks, such as cleaning every window in the school.

Eventually, Hitomi ordered Sachi to “stop a test” from happening. Unable to conceptualize a peaceful or practical method to fulfill the request, and operating under her rigid compulsion to obey, Sachi responded in the only way she could imagine: she set fire to the school building. The incident served as a stark revelation of her ongoing psychological trauma, and as a result, she was eventually placed into Mihama Academy, a secluded institution designed to accommodate and rehabilitate students with troubled pasts.

Housekeeping Proficiency
Sachi excels at all standard household tasks, including cleaning, laundry, and organization skills she performs with exceptional precision and dedication. While her cooking abilities are not directly shown, it is implied that she is competent, though Amane Suou once noted that Sachi’s perfectionist tendencies might make her difficult to work with in the kitchen, as she tends to focus too long on individual components of a meal.

Mechanical Engineering and Explosives
Sachi possesses a surprising aptitude for mechanical systems. She regularly maintains the dormitory’s plumbing and demonstrates advanced knowledge of explosives. In Grisaia no Kajitsu, she constructs functional, simple explosive devices. She later trains under Yuuji Kazami to develop bomb-disarming skills and successfully applies them in Grisaia no Rakuen.

Melee Combat
Despite her mild personality, Sachi is proficient in close-quarters combat. While the exact martial art she practices is never specified, she showcases formidable fighting ability. In Grisaia no Rakuen, she single-handedly defeats multiple Ichigaya agents using only two kitchen knives. Notably, she shows visible disappointment when instructed by Kazuki Kazami to subdue the agents without lethal force.

Wit and Intelligence
Sachi is portrayed as highly intelligent throughout the series, with her analytical thinking and problem-solving ability being a central element in her personal storyline. Her intelligence, paired with her obedience and precision, makes her both a reliable ally and an unexpectedly resourceful character in high-pressure situations.

• Yuuji Kazami: Sachi and Yuuji were childhood friends for a brief period, though Yuuji initially failed to remember their connection upon their reunion at Mihama Academy. Sachi attempted to jog his memory by referring to him as “Yuu-kun,” but was disheartened by his lack of recollection. Over time, Sachi grew envious of Yuuji’s ability to help others particularly Michiru and Yumiko and began quietly observing him, much to his irritation. However, after Yuuji finally remembered their past and helped Sachi confront her trauma, she developed genuine romantic feelings for him and began using “Yuu-kun” more frequently as a sign of endearment.

• Yumiko Sakaki: While not especially close to Yumiko, Sachi was initially treated with caution by her. Yumiko considered Sachi a potential threat due to her unpredictable behavior and kept a watchful eye on her at least until she came to trust Yuuji and his influence over Sachi’s development.

• Amane Suou: Amane often acts as a grounding force for Sachi, gently steering her away from taking jokes too seriously or from over-performing tasks due to her literal interpretations. Amane serves as a supportive figure, offering guidance and preventing Sachi from exhausting herself unnecessarily.

• Michiru Matsushima: Sachi and Michiru share a friendly and humorous dynamic. Michiru frequently seeks Sachi’s assistance, and Sachi enjoys teasing her in return, particularly when Michiru acts dramatically or makes exaggerated statements. Sachi is notably the only one to call her “Michiru-sama,” most likely as a playful gesture.

• Makina Irisu: Sachi and Makina form a close bond over the course of the series, especially in Grisaia no Rakuen, where both display courage and resolve in efforts to help rescue Yuuji. They are often seen together, particularly when watching Tuna Man, and share a mutual enthusiasm and boldness during high-stakes moments.

The given name Sachi (幸) means “happiness” or “good luck,” symbolizing her parents’ heartfelt wish for their daughter to live a joyful and fortunate life.

Her surname, Komine (小嶺), is composed of 小 (ko), meaning “small,” and 嶺 (mine), meaning “ridge” or “peak.” Together, the name may evoke the image of a modest mountain ridge, possibly reflecting her gentle nature and humble disposition.