Hi there! First of all, thanks for playing Tomai! I'm glad you like it!
Secondly, this game, and lots of other similair games-- are made with a program called Ren'py. It's a free to use program that's always updating and very easy to pick up, imo. It does require "coding" -- but please do not be intimidated by this.
Ren'py gives you a base framework to work with, and all you need to do is write up the script, where images show up-- and if you wanna get REALLY complex about it; you can do routing, etc, etc. So in this way, it's one of the least coding intensive programs to make games out there right now. But most starter games don't need that, and I highly suggest you make a very simple game for your first. (This was mine!)
People think a game needing coding is somehow a BE ALL END ALL to their game making career-- but the truth of the matter is; any program that promises "A coding free experience!" when helping make your game is usually just getting you to SECRETLY code behind some pretty looking buttons. (Also, those programs are usually ones you have to pay for; which is not always a great thing for beginning game devs!)
So, my thinking is-- if you're going to be tricked into coding by another program-- you might as well just learn the basics in Ren'py. It's very simple once you just learn what each piece and part is and means. Plus, the community is great and super informative and Ren'py itself comes with an easy to understand tutorial.
Any game will require a kind of coding or programing or behind-the-scenes puzzle solving to get to that finished product. If you're not ready for that kind of thing-- all I can really ask is; are games for you? If the process of putting together the game scares you so much that having to code even one line ruins your desire to make games-- you might want to consider another position. Maybe a collab with a programmer? Maybe helping fund someone else to make your idea? Or maybe not a game at all-- what about a comic, a novel, a twine? You've got options!
Whatever you chose though, go into it with confidence and an open mind. Go into it knowing it's not going to be easy at first-- but with time you will begin to understand the process; it's just about not giving up! You got this!
Oh! And next time you're curious what a game was made in, you can click the "more information" link on the profile of any Itch.io page and most people have their tools listed out. Here's Tomai's as an example:
(The button is usually right above the download button!)
Hope this all helps! Have a good day!