You found a link that says "4K," but it looks like 480p. Here is the technical fix:
When searching for crisp anime aesthetics, specialized wallpaper hubs and artist portfolios offer the safest, highest-quality image files.
Anime art has evolved from a niche subculture into a dominant global visual medium. With the rise of high-resolution displays, fans are constantly searching for crisp imagery to personalize their desktops, phones, and tablets. Finding high-quality anime wallpapers requires understanding resolution standards and knowing where to source legal, safe, and high-fidelity art. Understanding Wallpaper Resolutions
If you cannot find the perfect image, consider upscaling. AI tools like Waifu2x (waifu2x.udp.jp) allow you to take a 720p "sexy anime girl" image and upscale it to 4K or even 5K without losing quality. The neural network smooths lines and removes JPEG artifacts.
Here are some of the stunning anime sexy girl wallpapers you can expect:
