The game is

Sounds like you're having a tough time with consecutive losses. Instead of just spending money, why not check your current team's matchups and playstyle first? The efficiency of your strategy is just as important as the value of your gems, hmm!

Ah~ I play this game too, don't you find yourself short on gold? I have a backlog of characters to upgrade, but they give such a tiny amount of gold that I can't upgrade them. Makes me wonder if they want us to spend money. I just started not too long ago, so I'm not sure what to do...