You and me both, fellow.
Exploring a bit into how it might fail: AFAIK Japanese people shun tips because it is seen as an unwelcome incentive to do better, and they take pride in doing their best wherever. Tipping, thus, is akin to saying "This should motivate you to do better next time" - basically an insult. This is said in the site you linked to as well, it quotes a testimonial from an employee that didn't quit an oppressive job she had because a customer complimented her work. Not because of a silent tip and a nod.
An app that intends to 'remove friction in tipping' and 'motivate employees with tips', goes against Japanese cultural values very hard. The workers are (allegedly) not motivated by tips and tipping doesn't have a friction problem unless you're the owner/manager trying to get in on it. Additionally, this is something the workers have no input on, it is a terminal on a table whose sole purpose is to add tips to the service. No employer would ever allow its workers to do this just because, let alone pay a company for this service. There has to be a split of some sorts embedded into the game, which leads me to think this will motivate only prospective employers looking to get a cut on the tip income.
According to the site, the terminal only asks if you want to tip and the customer says yes or no, with a tick note appearing in the terminal if the customer says yes. This could help cover tip stealing. How would you ever know your tips were stolen if you didn't even know you were tipped in the first place?
So not only are they importing the tip system from the United States, but also the adversarial relationship between hosts and owner/managers that encourages tip stealing, and a form of tip stealing that the workers can't stop because it's in an app controlled by the owner/manager, not a jar tallied at the end of the day by the same workers that filled it.
Maybe I'm reading too deep into it, I tend to do that sometimes.