Now, the funny thing about this, is that when I was playing the game I thought, "man, this font looks really familiar... Wait, is this a font that I designed?" Sure enough, after some extensive researching, I found a Github repository for this game(the Japanese version, but still, same-ish source code). After digging around through the repositories files, I found that yes, the subtitles are in fact in Helvetihand! How badass, one of my fonts ends up in a game made by Square. I'm honored. But, here is the kicker... They used Helvetihand Italic for some of the subtitles(like in the screenshot you posted). I never made an italic version. They have my original font file(normal Helvetihand) and an italic version that I suppose someone at Square made themselves and never published? Either way, same font, just italic.

HelvetiHand

Simplon Mono