Because Japanese is the native language of these productions, Western audiences rely on subtitle groups (or "fansubbers") to translate the dialogue. Finding a release with an "Eng Sub" tag signifies that the video file includes hardcoded or softcoded English text translations.
Whenever possible, check major streaming platforms (such as Viki or Netflix) to see if the title is available through legitimate, high-quality streams.
The phrase " " refers to a specific adult film title produced by the Japanese studio (Style One)