Firefly (Honkai: Star Rail)

Firefly's character illustration was first revealed on December 15, 2023, during a promotional livestream for version 1.6 of Honkai: Star Rail. She made her first appearance as a non-player character in version 2.0 of the game on February 6, 2024. On April 23, HoYoverse released her official character artwork. In mid-June, they released trailers for her character story and gameplay, as well as an animated short featuring her called The Embers of Glamoth. Firefly became a playable character in version 2.3 of the game on June 21, 2024. HoYoverse also introduced her signature Light Cone, Whereabouts Should Dreams Rest, on that date. In her human form, Firefly is depicted as a young, shy girl. Her outfit is based on the kogal fashion style often seen in Japan, resembling a school uniform, as well as with a headband. In version 3.4, a purchasable skin was released for Firefly, which is designed to more closely resemble traditional sailor fuku school uniforms worn in Japan. As SAM, Firefly changes into a mechanical form and can switch between her normal human form and said mechanical form in-game, being one of only a few characters who can switch between forms during battle. The name "SAM" was already familiar to players before Firefly's true identity was revealed. SAM was first mentioned in the in-game database text in version 1.0, and the name was also referenced in an event in version 1.1 by the character Silver Wolf, one of Firefly's fellow Stellaron Hunters. In the lore, SAM is the abbreviation for Fyrefly Type-IV Strategic Assault Mech, the combat armor piloted by Firefly, while Firefly herself is a genetically modified soldier created for battle. After the fall of Glamoth, she was imprisoned and suffered from a genetic illness known as Entropy Loss Syndrome, enduring its pain while searching for the meaning of life on her own. Both Kusunoki and Fisher share similarities with the character in having chronic illnesses; Kusunoki has been diagnosed with the arthrochalasia type of Ehlers-Danlos syndrome, while Fisher has juvenile idiopathic arthritis. Fisher shared in a livestream that her arthritis has made walking difficult and often requires hospitalization, making her feel as if she had been put on pause while everyone else was moving forward. She resonated with Firefly's story during her audition and burst into tears later. Firefly is voiced in Chinese by Song Yuanyuan, and in Korean by . SAM is voiced in Chinese by Gan Ziqi, in English by Adin Rudd, in Japanese by Jun Kasama, and in Korean by . == Appearances ==

Story Firefly is a genetically modified human created by the interstellar nation known as the Republic of Glamoth, engineered as a living weapon to fight against the Swarm, one of the game's main antagonistic forces. She underwent genetic enhancement, but her body gradually deteriorates due to Entropy Loss Syndrome. She explains to the Trailblazer, the game's main protagonist, that this condition causes her body to decay over time, causing a detachment from reality that progressively gets worse. Eventually, Glamoth and the Swarm annihilated one another, leaving Firefly as the sole survivor. In her grief, she awakened SAM's enhanced combat state and set out on a journey across the cosmos to find the meaning of her own life. After joining the Stellaron Hunters, she adopted the alias "SAM" and primarily participated in missions in her mechanized form. During their tour, they unexpectedly encountered Sampo, one of the Trailblazer's old acquaintances who secretly followed them for a time before being noticed. Sampo recommended they visit an amusement park attraction; after they did so, he discreetly warned the Trailblazer that Firefly was lying about being a local. Later, during the tour, Firefly admitted she had been hiding something from the Trailblazer and invited them to her secret base in the Dreamscape to explain everything. There, she confessed that she was a stowaway and told the Trailblazer about Entropy Loss Syndrome, though she did not yet reveal her full identity. After returning from the Dreamscape into reality, Sampo appeared again: it was revealed that he was actually Sparkle in disguise, a member of another faction known as the Masked Fools. Sparkle then transported the two of them into a strange dream where they were trapped and forced to confront various monsters. They eventually escaped under cover provided to them by Black Swan, one of their allies. Back in reality, Black Swan sensed that Firefly had re-entered the Dreamscape and was being pursued by monsters. The group went into the Dreamscape to search for her. Firefly and the Trailblazer were reunited, but were ambushed by monsters. Gravely wounded in the attack, Firefly died in the Trailblazer's arms, leaving them devastated. She explained that her previous "death" in the dream had allowed her to reach a hidden deeper layer of the Dreamscape and learn how to access it. She then brought the Trailblazer into this deeper dream, where they reunited with the rest of the Astral Express crew, the game's main protagonist faction. Within the deeper Dreamscape, the group learned that all of Penacony's dream realm was on the brink of collapse. To resolve it, the group sought an audience with Sunday, the planet's ruler. Sunday revealed that he had betrayed the Path of Harmony once upheld by the planet's rulers and instead pledged himself to the Path of Order, intending to transform Penacony into an endless, beginningless dream. This ideological divide led to a decisive battle which ended in the Trailblazer's group being defeated and drawn into Sunday's dream. Firefly confronts the Dreammaster and prevents the Swarm's manifestation, enabling the Express to shatter the Order's illusion and confront Sunday. However, later at the Radiant Feldspar, Firefly reveals that the Order's brief merging of the dreamscape and reality has worsened her Entropy Loss Syndrome, causing her to disappear. The Trailblazer then invokes the Path of Finality's power, altering the past and fulfilling Firefly's wish to see the fireworks. In the present, Silver Wolf contacts the Trailblazer with news of Firefly's awakening and recovery, hinting at their future reunion. Character gameplay Firefly is a 5-star Fire type character who follows the Path of Destruction. When exploring the overworld, her Technique allows her to transform into her SAM form, leap into the air, and move freely while airborne. She can also perform a plunging attack that strikes enemies within a certain area. In combat, Firefly fights entirely in her SAM form. Her Ultimate ability enables SAM to enter an enhanced state, significantly increasing her offensive power. == Promotion and collaboration ==

HoYoverse ran a physical advertisement campaign featuring Firefly in Japan Railways train stations in Tokyo in early June 2024. They also launched a real-life promotional event called Super-Distance Communication, where players could speak with Firefly over three consecutive days. Each day featured different content and interactive elements. An action figure based on SAM was released in a partnership between miHoYo and Bandai Spirits in June 2024. In 2025, miHoYo and Good Smile Company partnered to release a decorative figure for Firefly, which is scheduled to release in the fourth quarter of 2026 in Japan and the second quarter of 2027 elsewhere. A Firefly-themed computer case with accessories was announced in a partnership between miHoYo and HYTE in August 2025. == Reception ==

Firefly was received well by critics and players alike. Players created large amounts of fan art, commissioned illustrations from artists, and produced other fan works to express their affection for her. Once Firefly debuted as a playable character, a surge of fan creations appeared on Chinese social network Bilibili, including MikuMikuDance videos, hand-drawn animations, and original animated projects. Some fans even showcased handmade SAM mech armor at conventions. With regards to her character trailer, Guan observed that Honkai: Star Rail often conceals character information within its marketing materials, encouraging players to actively piece together details alongside in-game hints to complete the character's image. Through this interactive process, the developers gradually deepen players' impressions and emotional attachment, enabling later plot points such as Firefly's "death" and identity revelation to deliver a more powerful emotional impact. Firefly's later revelation of her true identity was described by Ku as highly dramatic. Guan commented that the player's first interaction with her felt like a date. Through the sequence of her showing the Trailblazer around Penacony, she writes, the game establishes an initial emotional bond between the two. Guan argued that such delicate character development lays the groundwork for a deeper and more layered character arc. Some players even placed a mock memorial for her in front of an official HoYoverse gashapon machine at an event in Tainan, Taiwan, complete with a black-and-white portrait, incense sticks, joss paper and offerings, to mourn her in-game passing. After it was confirmed that Firefly had actually survived, anticipation quickly grew for her to become a playable character. Commercial performance On the day of her playable character release, in-game sales in Honkai: Star Rail caused the game to reach the top of the iOS best-selling list in China, rising from 37th place. According to Game Daily, the animated short "The Embers of Glamoth", which features Firefly, reached over 2 million views on YouTube within 10 days of its release. Firefly consistently ranked within the top three in popularity polls and fan-creation contests across major social media platforms after her release. == Notes ==