The longer I play Gakumas, the more impressed I am by the depth of a lot of its character writing as a mobage, not unlike how I first felt about Uma Musume. There's a lot of silliness, especially in the main plotline, at least insofar as I've gotten, but there's also a ton of earnest, heartfelt stuff in the individual idols' stories that I've been enjoying immensely. I just got the true ending for Rinami Himesaki, whose whole deal is she's a third-year student on the verge of graduating who had given up on ever breaking out as an idol, and man, it almost feels like a waste to have her in a free-to-play game when she easily holds her own as one of the best galge heroines I've seen in a long time. Just some genuinely touching, dorky chemistry with your character who wants to do his best to make her dreams come true after all the kindness and support she gave him in their younger years.
Idolmaster has pretty much always had fun character writing from the beginning and it's definitely a big reason why so many of those characters are beloved as the franchise approaches its 20th anniversary about a year from now. But speaking as someone who's spent a decent amount of time playing that original incarnation, it's hard not to be floored by just much more confident and textured the dialogue feels at its best. It's not without its fumbles, largely with other characters in the game, but I feel pretty confident in saying that if you only have it in you to do the grind to see one character through to the end (and I wouldn't blame you, as much as I've come around to the gameplay loop!), Rinami is the one to go for. Even as someone with a soft spot for a lot of Idolmaster's oneesan characters, I've never seen one quite like her and she's gonna be on my mind a whole lot even after I put this game down eventually.
Anyway, Gakumas is a dope character raising sim and if you're a fiend for deck building games in particular and can read Japanese, I highly recommend giving it a download. And if you're Namco and you're thinking of localizing this thing (which you absolutely should!), you know where to find me. 
