[Honkai: Star Rail] In My BGM, I'm Invincible

[New Novel: Honkai: Star Rail, but an Aeon RPG is now underway] Rachel transmigrated. Eighteen years later, as a freshman at Paperfold University, she suddenly discovered that she had embarked on the Path of Harmony. She could hear and alter the world's background music, and gain different supernatural abilities based on the music. This was perfect, except for one tiny problem: she was at Dreamweaver Academy. Cyberpunk civil engineering, working construction online, but also a karaoke queen...? Well, that could work too. * Thanks to the song "Good Fortune Is Coming" she sang before the interview, Rachel successfully got into Dreamweaver's freshman internship program. On her first day working construction on the border of Dreamweaver, Rachel saw a girl in a green dress with white hair, holding the hand of a gray-haired Trailblazer as they ran past her. How lovely, that romantic atmosphere. Rachel instinctively wanted to cue up "Love Loop" for them, but before she could do it She heard a Japanese song that sounded vaguely familiar. Before she could remember what song it was, the BGM switched to the next one, as if afraid she might not understand its meaning. "A new storm has appeared! How can we stand still and not press on?" Rachel had secretly followed them and, some time later, watched the girl in the green dress transform into a gigantic mech: ...! So that first song was actually a Kamen Rider theme song! There's only one truth! So you're the Penacony stowaway! * Rachel stumbled into Penacony's massive conspiracy and scraped by to the end with the help of her BGM. Now it was time to awaken everyone sleeping in Ena's Dream! Rachel: Um, actually, I have a plan that's a tiny bit safer than yours. Under Miss Robin's curious gaze, she silently switched the BGM to a school bell, then began her performance: "Gently knock on the sleeping heart, slowly open your eyes..." Sunday: I have no idea! How did they all suddenly wake up? * At last, the massive crisis was over, and Rachel returned to Paperfold University to continue her studies. Life without BGM was peaceful, but wonderful. Rachel continued her studies while sheltering Sunday, the former head of the Family and current wanted fugitive. Now and then, she would remotely send a rendition of "How Lonely It Is to Be Invincible" to Xianzhou through the Trailblazer to buff them up. Life was carefree and pleasant. Sometimes a BGM would start playing, something like "Sleepy Banana Monkey is such a good banana, banana, banana, banana," but she'd switch it to "Little Er Lang carries his schoolbag to school" with the blank stare of a subway passenger looking at their phone. She thought life would stay this easy and pleasant forever, and that the troubles she'd gone through were only a brief interlude, until one day. The somewhat familiar Black Swan appeared before her and asked, "There's a fascinating world where you could put your skills to use. And I don't just mean music, but architecture, too." "That world is in ruins and urgently needs skilled people to help rebuild it." "Would you be interested in coming with us to Amphoreus? I mean you, and Mr. Sunday, whom you've been hiding." Rachel: ... She pondered for a moment, then asked, "Will I get an internship credit stamp?" Bonus scene: Hiding Sunday has had an almost entirely positive effect on Rachel's life. Mr. Sunday is an absolute kind man, a beauty, and a wise man... It would be even better if "Ode to Order" didn't occasionally ring out around the house. But Rachel was nearly used to "Ode to Order," until one day she opened the front door and the song she expected was replaced with: "Who dares cross the love barrier?" Rachel: ...Huh? Coming soon: [Genshin Impact] How to Go from NPC to Five-Star Character Blurb: By the time I first realized that the world I'd transmigrated into was a game, I'd already been living a happy life in Liyue for twenty years. I didn't feel like the sky was falling. I was just curious who the game's protagonist was. By the time I first realized I was a game NPC, I was completely calm. Sure, game NPCs are disposable, but if the sky falls, Rex Lapis will hold it up... Wait! Rex Lapis is gone! Um, um, it's fine. We still have the Qixing and the Adepti. I can see it. Every single one of you is a five-star character! When I found out that giving a blond traveler something called Primogems could win their favor, and that if I could put together a version event and make the stages less complicated, or just give everything away for free, they'd cling to my leg and call me "daddy" or "mommy," while I could order them to do all sorts of things NPCs like us couldn't do, I looked at the mining certificates at home and the Primogems piled up with nowhere to put them, and felt conflicted. When I heard that plenty of NPCs had died in neighboring nations like Inazuma, Sumeru, and Fontaine, I panicked. It's confirmed: game NPCs are disposable! To stay alive, to keep enjoying my wonderful life in Liyue, and for that long-legged beauty with straight black hair! I have to become a five-star character. Surely the game developers wouldn't kill off a popular five-star character, right?! Theme: Live well