It's a "this is us" clone with a very very solid main plot. Honestly the love story in here is really sweet and it will hit you in the feels...
However, to me there were two major flaws that kept it from being great or honestly.. even very good.
Firstly, the musical aspect does not do it any favors, and this is coming from someone who typically loves musicals.. but in this it comes off really cheesy in part because all of the songs are played with their original vocals with cast lip syncing and dancing to the songs randomly thrpught the show, and because with the exception of the female lead (who does a wonderful job, she's the highlight of this whole show) the cast does a horrible job of lip syncing. 90% of the time they're just mouthing the songs with blank expressions on their faces.
Also their use of the singing cutaway is inconsistent, early in the show it's used whenever a character is feeling extreme emotion, later it becomes a bit more random and starts to feel like they're just putting numbers in at random places because they didn't want to have episodes w/o musical interjections.
Another concern I had was with it's treatment of secondary characters and secondary plotlines. I won't get into specifics but several times in the show some secondary character or another will get an episode and they'll get a little bit of their story fleshed out or there will be a hint at a secret or a part of the story you haven't heard yet only for that plot point to ultimately be abandoned altogether.
Maybe these characters will get more focus in a second season, but it didn't really feel that way.