Sakura joined HKT48 as a first-generation trainee in July 2011 at age 13, making her theater debut that November and receiving promotion to full member status in March 2012.1 Her trajectory through AKB48 Group's competitive election system was remarkable: she became the first HKT48 member to rank in the general election (47th place, 2012), climbed to 26th (2013), then 11th (2014)—earning enough votes to share center position with Mayu Watanabe on "Kiboteki Refrain," making her the first local HKT48 member to center an AKB48 single.1

By 2015, she placed 7th with 81,422 votes and released photobook "Sakura," which topped Oricon's weekly photobook chart. Her 2016 solo center on "Kimi wa Melody" (AKB48's 10th anniversary single) and her 2018 peak—3rd place with over 180,000 votes—established her as one of the franchise's top-tier performers. She balanced multiple roles: HKT48 Team KIV co-captain, AKB48 Team A member, and commercial model for brands from regional tourism to national contact lenses, all while performing in theater shows and handshake events.2

In 2018, Sakura entered Produce 48—a survival show pitting 96 Japanese and Korean trainees against each other. For a 20-year-old with seven years of established fame, restarting from zero was risky. But Sakura excelled: she received an "A" grade in preliminaries, was selected as center for theme song "Nekkoya," and secured 2nd place in the finale with 316,105 votes, earning a spot in IZ*ONE.3

IZ*ONE debuted October 29, 2018 with "COLOR*IZ" and "La Vie en Rose," marking Sakura's transition from Japan's theater-based system to Korea's high-budget K-pop industry. She placed HKT48 activities on hiatus for two and a half years, releasing three Korean mini-albums and touring Asia before IZ*ONE disbanded in April 2021.3

Sakura's gaming identity predates her idol career. She played League of Legends for up to 12 hours daily during early HKT48 years, and learned Korean through in-game communication with teammates—faster than through formal lessons. This bilingual gaming fluency prepared her for Produce 48 better than most Japanese contestants.4

In 2018, she launched YouTube gaming channel "ちゃんねる宮脇咲良," streaming Fortnite, Apex Legends, Splatoon 2, and Fall Guys. The channel reached 717,000+ subscribers and 25 million views by March 2025. Her gaming prowess gained mainstream attention at BlizzCon 2023 when LE SSERAFIM promoted their Overwatch 2 collaboration—Sakura was one of the event's best players despite her idol schedule.5

After IZ*ONE disbanded (April 2021), Sakura announced her HKT48 graduation on May 15, with a farewell concert June 19 at Fukuoka Marine Messe. She quietly signed with Source Music in September 2021, but the contract wasn't publicly announced until March 2022.6

Those eight months were, in her words, "the hardest thing." Unlike her 13-year-old debut or IZ*ONE's constant performances, this trainee period required intense practice without fan interaction or social media presence. "When I was working as an idol, I was used to performing on stage for fans, but it's different as a trainee, when it isn't being shared with the world," she told Weverse Magazine. She took formal Korean lessons for the first time and studied vocals/dance from basics despite her decade of experience. On May 2, 2022, she re-debuted with LE SSERAFIM—her third debut across two countries.7

LE SSERAFIM's January 2023 Japan debut with "Fearless" (Japanese version) sold 277,391 copies and topped Oricon's weekly singles ranking—the first foreign female artist to achieve this in 5+ years since TWICE (2017). The single earned RIAJ's "double platinum" certification, making LE SSERAFIM the first foreign artist to win the award with a debut single.8

By July 2023, Oricon named LE SSERAFIM Japan's top-selling rookie artist (1H 2023) with ¥1.18 billion ($8.19M) in sales—the first female artist to exceed ¥1 billion in the rookie ranking. Korean releases also dominated Japan: "ANTIFRAGILE" surpassed 100M streams, while albums "UNFORGIVEN" and "EASY" debuted #1 on Oricon with 117K+ and 140K+ copies respectively. Sakura's individual brand power—from her 2015 Oricon-topping photobook to ongoing endorsements with Lily Brown and Primera—positions her as K-pop's bridge to Japan.8