Maria Mikhailovna Kujou also known as Masha, is a supporting character in the series. She is a second-year student at Seirei Private Academy, serving as Secretary of the student council. Maria is widely regarded as one of the two most beautiful girls in her grade, alongside Chisaki Sarashina, and is known as the Madonna Maria is a kind and gentle person who always has a warm, fluffy smile. She is very caring and understanding toward others, making people feel comfortable around her. Even though she is sweet and thoughtful, she sometimes acts a little silly or forgetful, which makes her even more lovable. She believes that life shouldn’t be taken too seriously and prefers to go with the flow.

Ayano Kimishimais a supporting character in the series. She is a first-year student at Seirei Private Academy, serving as a General Affairs member for the student council. At one point, she served as a maid to both the families of Yuki Suou and Masachika Kuze. She seems very quiet and serious at first. She moves carefully, speaks in a calm and even voice, and doesn't show many emotions on her face. Because of this, people often don’t notice when she’s around. She prefers to stay silent and only speaks when necessary.

Ben is the financial and asset management director at Belobog Heavy Industries, and one of Koleda's trusted aides. "I enjoy mathematics, but that doesn't stop me from giving thugs a good smack." He's a burly and strong Thiren Despite his tough exterior, he's of a surprisingly sensitive and detail-oriented nature, especially when it comes to numbers. Originally a frontline mechanical operator at Belobog, his talents caught Koleda's discerning eye, leading to his promotion to a managerial position responsible for the company's finances. Grateful for Koleda's trust in him, he remains profoundly loyal to her. His favorite food is black caviar, but he dislikes fish.

Anton is a key member of construction staff at Belobog Industries and one of Koleda's trusted aides. "Got a job you can't handle? Leave it to me!" Anton is one of the top brass at Belobog, handpicked by its former president Khors, which makes him a "senior employee." A genuine, straightforward man, always boosting the morale of his coworkers with his surplus of energy. Apart from this, it seems Anton is always talking to his jackhammer, affectionately calling it, "Bro."

Firefly is a playable character in Honkai: Star Rail. A member of the Stellaron Hunters and a young girl clad in a mechanical armor "SAM." Born as a weapon, she's afflicted with the agony of Entropy Loss Syndrome due to genetic modification. She joined the Stellaron Hunters in search of the meaning of life, relentlessly pursuing ways to defy fate.

The Herta is one of the most intelligent beings in the Honkai: Star Rail universe. As Genius Society Member #83, she has contributed countless discoveries and advancements. However, her indifference to anything "boring" has led her to delegate much of her work to others, including the Herta Space Station, which she originally founded but abandoned out of disinterest.

Hatsune Miku, codenamed CV01, was the first Japanese VOCALOID to be both developed and distributed by Crypton Future Media, Inc.. She was initially released in August 2007 for the VOCALOID2 engine and was the first member of the Character Vocal Series. She was the seventh VOCALOID overall, as well as the second VOCALOID2 vocal released to be released for the engine. Her voice is provided by the Japanese voice actress Saki Fujita. There have since been numerous installments, such as additional voice libraries dubbed 'Append', as well as an upgrade for the VOCALOID3 engine, which contained an English vocal release. She received a VOCALOID4 update to her Japanese and English voicebanks in August 2016, as well as a Mandarin Chinese voicebank in September 2017.