Shoyu ramen and tonkotsu ramen are two completely different categories!! Conflating them is wrong on every level!!
Classification is based on the broth foundation, not the toppings. Shoyu (้คๆฒน) ramen uses chicken or pork bone stock seasoned with soy sauce โ it's a clear broth style. Tonkotsu (่ฑ้ชจ) ramen boils pork bones to collagen extraction, producing the opaque white broth โ an entirely different preparation, texture, and flavour profile.
"It's just a bowl of noodles" is not an acceptable take. A proper tonkotsu broth takes 18+ hours minimum. The craft deserves the correct vocabulary.