- Keep Circulating the Tapes: Many songs featured in the series (everything by the Latch Brothers, Guitar Vader, and most single songs contributed by artists) have yet to see any form of re-release. In some cases, the original albums (if they were even on albums) are difficult to find, meaning the games are the best and cheapest way to hear them.
- Also, wanna play JSRF? It's an original Xbox-exclusive and has seen no re-release so far. Luckily, it's readily available in all regions, and can be bought cheaply in the SEGA GT 2002 combo pack. It is also playable on a 360, albeit with lag spikes in many areas.
- No Export for You: Was once the case for the game's soundtracks, which didn't get an international release, physical or digital, until 2012. The only thing the states got till then were sampler CD's featuring a handful of licensed tracks.
- Pop Culture Urban Legends: For a long time, people were unsure if Future was originally meant to be for the Dreamcast. Since the game makes barely any use of the right analog stick, it would seem to be programmed for the Dreamcast controller. On top of that, it would make sense for them shift a new JSR project in-progress to a new console after the failure of the Dreamcast, and since the Xbox had a similar architecture and Sega was prepping to enter an eleven game deal for the system, it seemed the obvious choice (the third Toe Jam And Earl game went that way). Sometimes a rumor would pop up of it being confirmed that it started on the DC, and even a few times has this page had "it was originally for the Dreamcast" as an item. However, this Tweet by the game's composer finally puts the issue to rest: Future was always meant for the Xbox.
- Urban Legend of Zelda:
- With the many unlockable characters, it seemed natural at the time that Professor K must be playable — despite his incompatible character model (although he is unlockable in the GBA version). The same goes for the elusive Coin, too.
- Rumors once abounded about characters called Wave, Numa, and Check that had remnants in the Japanese version of Future. In more recent years, discs of all regions and editions have been combed over, and no such characters could be found.
- What Could Have Been:
- During the marketing of the first game's American release, a Sampler CD was handed out from select stores. This CD included songs that were going to be added to the American version, but never were.
- In an early build of JSRF, Yoyo had a smaller health capacity and might have been able to hold more than 30 spray cans (the spray can icon doesn't turn green on the footage of this build). Footage can be seen on this Xbox commercial at 0:09.
- A katana◊ for Hayashi was unearthed from the game's files, though a katana is never seen at any point in the game. This trailer from E3 2001 also shows a variety of differences. Gum sports a completely different dress, and Shibuya Terminal is practically unrecognizable. This other trailer also shows split-screen multiplayer in Shibuya Terminal, a fight against helicopters in the same area, and some minor differences to other levels.
- Fifteen minutes worth of unused dialogue has been unearthed here, detailing scrapped story elements, mechanics, and possibly bosses.
- A new JSR game was proposed by Headstrong Games for the Wii. Its concept art has circulated around the Internet for years. Sega reportedly shot down the idea, and Headstrong ended up making a new House of the Dead game instead.
- In late 2017, Dinosaur Games were commissioned by Sony to create a visual proof of concept for a new game titled Jet Set Radio Evolution. They then went on to present this video to Sega, who turned it down.
- Early concept art of JSR had the members of Poison Jam wielding baseball bats.
Trivia / Jet Set Radio