https://en.wikipedia.org/wiki/Japanese_curry

It’s much less spicy than most other curry. Even the “hot” versions are like barely detectable heat. It also often has apple and honey added for sweetness, and I would say it’s saucier than other curries. It’s good if you approach it as its own thing, but very different from like a British-style curry and even more different from anything you would find in India.

The product in the picture is a curry roux block, which looks a bit like a big Hershey chocolate bar with squares that can be broken off. It’s like a sauce concentrate. You start cooking your meat and vegetables in a pot, add just enough water to cover everything, then add cubes of roux. The roux has everything necessary to make a complete sauce, but lots of home cooks have their own blend of things they add to adjust, like the aforementioned grated apple and honey, or ginger, garlic, mirin, tonkatsu sauce, etc.

I’m not sure how to describe it, but its way different from my expectations and I feel like one day I’ll eat or drink something and say “it tastes kinda like japanese curry”

Imo it taste much better and the texture is better too, more “velvety”. There are variants of the photo that are sweeter/have apple flavour. I like the stock standard Java stuff. I added a link to the recipe I started with initially in the original comment since there’s a few of replies.