Gakuran is already available as a Roblox experience at the official Gakuran page. This site does not list a separate commercial launch date beyond the Roblox page.
Gakuran: Availability answer
The Gakuran release date question is different from a Steam or console launch question. Gakuran is a Roblox experience, and the official Roblox page is live. Players can use the official link to inspect or join the experience where Roblox permits access.
Gakuran: Page notes
The Roblox page is live and the saved game details include the universe ID, root place ID, live public stats, and update timestamp.
Gakuran: What not to infer
This page does not invent a separate release date, season, update roadmap, or event schedule. If the creator group announces dated updates later, the Gakuran release date page can be expanded into a fuller timeline.