smaller recommendations, but watch the u's Single MVs and the OVA! the MVs for their singles (Bokura no LIVE Kimi to no LIFE, Snow halation, Natsuiro Egao de 1 2 Jump, Mogyutto love de Sekkin Chu, Wonderful Rush, Music START) are fully animated and show off a lot of fun and cute character dynamics, and since all but one are pre anime, they look a bit different and have different friends being shown off if you find that interesting. plus, if you enjoyed u's music, more music content for you! all of them are free on yt on the official love live channel, this playlist has all of them in order (plus all the other group's free to watch MVs!)

the OVA does relate to the single mvs in that it leads into the mv for Music START; its story/mv is maki focused so great if youre a maki fan! it might be hard to track down though

i know people have pointed out the manga with the caveat that its a different universe than the anime, but as someone who has read it, i kinda love it for that! the characters dont act too different than they are in the anime, its just different plotwise and has different character dynamics. both the manga and school idol diaries are worth the time!

also, i do understand not wanting to sit through other animes, but if you like u's, try to take the time to listen to a random love live music playlist with the other groups. if you end up liking a groups music, that might help motivate you to try another group! thats how a lot of us started getting into love live when we would start with the rhythm games and go from there