Osaka sits in the densely populated Kansai region, with Bortle 8 light pollution across the metropolis. Darker skies require heading into the surrounding mountains: the Kii Peninsula to the south and the highlands of Nara and Wakayama reach Bortle 4 within 90 minutes, with Bortle 3 deeper in. Japan's humid summers bring haze and the rainy season, while autumn and winter high-pressure systems deliver crisp, clear nights. At 34.7°N, the southern sky is well placed for the summer Milky Way from a dark mountain site away from the Kansai light dome.