Even now, having beaten this game a few days ago and sitting on it, I still don't know how I feel about this game. Let me break it down into the good and bad to see what you think alongside me.

The Good

Build a Hero School...Kind of.
You start by being nominated (as a former alumnus) of this hero school as the new principal, as the current one is stepping down due to his wife (the high queen) starting to get older and unable to continue her reign, so he doesn't want to be away from her.
So you inherit this school which is kind of a dump. Problem is, you can't really...change the school. You can choose to add rooms and decorations and outside learning activities, but it's set on a small/medium/large style. For example, a Dorm Room is a Medium plot of land for you to build on. But once you've built the dorm...that's it. It's done.
Some rooms and buildings can be upgraded, and nearly all of them provide some mechanical benefit. (Bonus XP earned, extra stats, etc). But still it offers just enough 'base building' to have kept my interest on that part.

Adventuring...Kind of.
So you have three teams of up to four students for a total of twelve. There are errands, which you send a team of 4 away to do it offscreen, which takes anywhere from 4-12 weeks, or you can do the main missions, which you directly control the students. The AI is...passable, I guess. If they engage in battle with an enemy they don't really move or back off, so any of their special attacks can very quickly kill them. It's usually best to get ranged allies and play as the tank role to keep the enemies at bay.
Levels are either randomly generated or just drawn from a large number of possibilities, and play kind of like Diablo-lite, with that same perspective, breaking barrels and beating up enemies for EXP/loot. So while you'll rarely see the same level twice, a lot of them feel the same, but an adventure only takes 5-10 minutes, so it's great if you just have a small amount of time to kill.

Class Customization...Kind of.
Every new student starts with the 'Student' class, which is a pretty weak melee one. Eventually you unlock the knight, rogue and magi, which are a tank, physical attacker and ranged attacker.
The knight eventually can become a Paladin or a Dragon Knight, which are a Tank/Tank or a Tank/Attacker. The rogue can eventually become a Harlequin or ... I forget the name, but they used guns. But both attackers, one melee, one ranged. The Magi could become a better magi or a healer. So while it seems like a lot, there's really only 6 endgame classes, and as mentioned, with the mediocre AI, it's best to limit your allies to the Gunner or Magic Classes (or healer).

Lots of Equipment...Kind of
With the aforementioned classes, there are about 12ish different weapons within each weapon type. 12 or so Daggers, which are Students, Rogues and Harlequins, 12 or so Swords, which are Knights, and Dragon Knights, 12 or so Hammers, which are Paladin only, 12 or so Guns, which are gunner only, and 12 or so Staves, shared by all of the magic classes. And admittedly at the highest tier, there's about 3-4 'Legendary' ones, so there is some diversity.
There's also like 50 accessories, but they're pointless. As an example, a mid-tier weapon may add 150 attack power, 15 Strength, 20 armor. A Legendary-tier accessory may add 3 Strength, 15 HP and 10 MP. It's wild how little they matter.
As a final note, there are three legendary weapons, which are a Dagger, a Sword, and a Staff. Which means that if you want to use them all, your final team needs a Dragon Knight, a Harlequin and a Caster. There aren't even four. I don't understand.

The Bad

Unexplained Stats
You've probably picked up that there are a number of stats in this game. In total, it's HP, MP, Attack, Armor, Luck, Strength, Dexterity, Intelligence. HP is fairly straight-forward. MP is for your special moves, which all classes get...but AI doesn't use them. Only you do. So while you can switch between characters to use them, generally in the heat of combat you're trying to lead enemies away from harming your allies so doing so isn't done often, so MP doesn't do much. Attack power also is self explanatory. The rest...I have no idea. I think Dex impacts your hit/dodge chance, but it's not said anywhere. Strength doesn't seem to have a noticeable impact on damage and Int doesn't on your special moves (which is what I'd assume it'd be). Really Attack Power and HP are by far the most important.

Leveling Students is a Pain
This'll mostly be a quick note, but as I mentioned, you get 3 teams of 4. Usually, 2 of those teams will be on errands that last up to 12 weeks of game time. Which means you have one team that can either A) tackle important story content or B) level students to graduate.
That's a piece I guess I neglected to mention. At the end of each semester (4 months in-game) you have to graduate students, at least one. They have to be at least level 10, and putting them in a new class starts them over at 1. But juggling the leveling of these students while also advancing the plot when you have one team you can do that with is restrictive and limiting, especially because you can get more students not assigned to a team, based on the number of dorms you built. They don't get passive or partial EXP and sit at level 1 til you use them. It's just mind-boggling.

Plot is Serviceable at best.
Mostly it's the fact that there's this disconnect between what's happening and the impact I personally felt. Spoilers to follow if you care, but eventually the High Queen passes away, and while she has a daughter (who is like 50-some years younger than her, it seems like), no one knows where she is, so the five Regional Queens (it's a Matriarchal Society) all seem like they're vying for the throne.
This could be interesting, and there are several missions introduced for each of the queens, and the game gives you a brief tutorial that doing missions for a particular queen can increase your reputation with them.
So initially I thought this would play a little like the early Armored Core games, where favoring a particular one would lead to you allying yourself with them against the others. So I picked my favorite and only did theirs, but nothing happened, and eventually I moved onto the others as I progressed further in the story.
There was also a cult of some kind who was trying to use the Princess' blood to summon some extraplanar deity (which they do succeed and you beat the ever-living tar out of it if you're appropriately leveled) that never really seemed to go anywhere, or explain their existence.
Eventually (getting back to the Queens) it turns out that doing their missions just allowed them to support the Princess to take the throne (even if she doesn't want to (another plot point that goes absolutely nowhere)). She's got a young guy guarding her most of the time who isn't from the same empire, and it's implied there's some sort of love interest there, but they're just kind of thrust upon you without much explanation and a mission or two of loredumps about the relationship, how they came to be friends, etc but you don't really 'see' them ever actually showing any caring.
At the coronation, after beating back the cultists and getting the queens to support the princess, another country, (of which the princess' guard is the son of its leader (gasp!)) attacks and the final battle takes place at the academy, and all your teams are present, fighting against the enemies which was admittedly kind of cool.
And then the game ends. I just...don't know what I was supposed to feel.

The Final
Okay that didn't help at all. There's more good than bad, but the other review that mentions it as a 'glorified mobile game' isn't too far off. It's great to pop on for like an hour, update your school, do a few missions, and then back out. It's got just enough customization and interactive playtime to keep interest, and the plot, while goofy and disconnected, is at least coherent enough to tell a single story.

I'm going to say it's "fun" but not "good". It's like the game version of the movie Venom.