Yes. All modern versions (macOS Catalina to Sonoma/Ventura) include the full Hiragino Sans family, including W9. The font file is typically located at /System/Library/Fonts/ヒラギノ Sans.ttc .
Hiragino Sans W9 is the ultra-bold weight of the Hiragino Sans (also known as Hiragino Kaku Gothic) family, designed by SCREEN Graphic Solutions hiragino sans w9
Designers call it "solid" because it solves the "ink trap" problem. In many heavy fonts, the complex strokes of a Kanji character (like 龍 for "dragon") would blur into a black blob. Hiragino Sans W9 is engineered with that keep the white space visible even at its thickest, making it the "Gold Standard" for professional Japanese typesetting. Hiragino Sans W9 is the ultra-bold weight of
Because of its extreme thickness and impact, "paper" in this context often refers to its application in : Because of its extreme thickness and impact, "paper"
By mastering this specific weight, you elevate your design from "generic Japanese text" to "intentional, Apple-native typography." Whether you are a seasoned type director or a developer adding that final polish to a bilingual app, remember: In a world of infinite fonts, the boldest choice is often the right one.