When a musical group has gone on to become especially popular, it's customary for them to put out a ‘greatest hits’ compilation: a collection of the songs that were most successful, that they're most well-known for. Such releases rarely offer much new on their tracklist, instead serving to have a handy selection of their most quintessential elements for established fans to throw on when they're just in a mood for the group's music overall. These also serve as an opportunity for new listeners to sample and see if they might be interested in going back and getting into the group's full catalog. These releases are fine on their own, generally inoffensive, but in spite of the ‘Greatest’ label, generally don't represent the act at their fully-realized best, just due to what they're overall trying to cover. Bushiroad's BanG Dream! has proven itself as a consistent, ongoing success, with the in-series band Roselia as a performing powerhouse. With that in mind, the role of Episode of Roselia I: Promise makes sense, for better or for worse, it's a greatest hits release.

Going into the film, the main question is exactly what kind of story Promise is going to be. It initially comes off like it's going to be a telling of Roselia's origin story, something that's been chronicled previously in other offshoots of BanG Dream! media. However, the familiar beats of getting the band together take up only roughly the first third of the movie, before we're treated to a montage across a moderate timeskip, and things shake up. What we instead end up getting effectively feels like three episodes of a Roselia-focused TV show, welded together across the timeline of their journey to Future World Fes, with a couple of montages and flashbacks covering for some gaps between the stories, along with attempts to bookend things between an emotional arc for Lisa. Variations on this kind of structure aren't uncommon for some anime tie-in films, and the stories as presented here mostly feel complete, with a major exception concerning the first one, but the connective tissue between the segments can feel exceptionally tenuous at each story shift.

That first section of the movie, depicting Roselia coming together, isn't really this piece's best foot forward, limited with the most clear-cut examples of what doesn't work here. As I said, this origin is a story that has been depicted in other places previously, and as a result this telling doesn't seem exceptionally interested in covering every aspect of it. Several of the resulting trials and tribulations from the band's formation are almost immediately skipped over in montage format, and while some of this had been glimpsed in prior BanG Dream! anime, much of it is material from the continuing story in the BanG Dream! mobile game that this movie is adapting all of its material from. That would be where the idea of this as a ‘Greatest Hits’ entry comes from, since the ‘episodes’ in this Episode of Roselia are in fact cherry-picked stories from that central source material.

As such, it means that not only do a lot of the continuous elements of those stories get glossed over, the long-term development of the characters (originally told over the course of different arcs over multiple years) that leads to how they behave in those stories can suddenly switch with little indication in each chunk of the film. Probably the most noticeable case of this is Sayo, whose early-series all-business attitude is prominently on display in the film's opening third, before things skip ahead to find her much more personable. It's a change that the characters discuss in-story as coming about due to experiences in stories not shown in this format, only momentarily flashed back to. It's a fair enough nod for the audience familiar with this franchise already, and at least signals to newcomers that something happened to cause this shift in a character they've already been following for half an hour. But it also majorly contributes to this feeling less like a contiguous narrative and more like, well, an adaptation of loosely-connected mobile-game stories. And that loose allusion to Sayo's development just barely serves its function in getting the story across here, apart from other instances in Promise where its telling of stories is fully incomplete. A major example of that is the detail of Lisa's fingernails, which is noticeably set up in the early minutes of the movie, only for any payoff to pass by unremarked-on. That's a key character moment in the original version of the story that instead comes off more as a mere Easter Egg here.

The presentation of all this as a Roselia-focused feature does allot it the opportunity to feel distinctive. Apart from the more colorful antics of Poppin' Party and RAISE A SUILEN that dominated much of the TV anime, Episode of Roselia feels like BanG Dream! at its most grounded and serious. The girls of the group all have their own expressions of outsized personalities at times, especially Ako, but for the most part these stories are driven forward by serious dialogue and calls for reflection between the girls. That makes sense, with these being plots based on visual-novel-style mobile-game stories, and marks Roselia's entries as likely the best fit for that kind of adaptational format. And it works because Roselia's story of striving for success feels like it can be treated with this level of seriousness. It also means that the production can seem a good bit more understated than usual. This movie doesn't have the same kinds of opportunities for cartoony-style CGI sakuga like we've seen SANZIGEN has been able to perfect in the latter TV episodes of BanG Dream! or their more recent D4DJ. It instead has the looks of a grounded drama, the skills of the studio put to use making sure characters still move in slight nuances during the multitude of motivational conversations. There are a few exceptional flourishes, like Lisa's bursting-blue flashback as she realizes the kinds of lyrics she wants to write, but for the most part the heightened drama is more carried by some exceptional vocal delivery from the actors, with the animation kept in check until it's time to whip around with more extravagant effects for concert scenes.

It of course wouldn't be a BanG Dream! feature without music, but there's another surprise here in the more restrained use of it. There are only a couple of full concert performance scenes in the movie, featuring all the effective music-video sensibilities SANZIGEN have honed throughout the years. But other musical inclusions encompass incomplete audition performances, or even solo vocal showcases and an acapella reading of a song by vocalist Yukina, whose seiyū Aina Aiba really shows off her chops across all these variations. It can feel a bit oddly lite for something that exists at the behest of selling all this music, but actually does fit with the more naturalistic progression these stories have (when they aren't awkwardly jumping to one another, of course); Much of the movie uses extremely understated background music or even lacks it altogether, allowing the diegetic songs to act as climaxes as each stories reaches its heights. And with how story-centric so much of this music is, I also have to praise how we finally have a BanG Dream! anime with full subtitles for all of the songs across the entire thing! Can I get a hallelujah?!

As a presentationally-effective method of whiling away three episodes of content with Roselia, does Promise work? As I said, it's got the Greatest Hits feeling more than anything else: Putting a glossy coat of cinematic paint on a highlight reel of the band's fictional journey so far. And in spite of those aforementioned missed moments with Sayo and Lisa, this movie does hit some of those other big moments fans of the band will know and love. Through all that, there's also consistency of message, Promise sticking very close to the BanG Dream! franchise's central theme of the fun and friendships in bands being their own reward. It's just that the format really calls into question if this was the best way to approach delivering this material. It can feel jarring in places, particularly with the second story in the way it's predicated on the growing closeness of a band we barely saw getting together in the opening minutes. That sense of incompleteness is the most direct comparison to one of those catalog pick-and-mix CDs it's so reminiscent of: Established fans will get a good selection of stuff they already like, newcomers will probably find something that catches their interest to go back and appreciate with the full context on their own time, but it overall doesn't stand as well on its own as the material that established it.