2 Watch Online — Shounen Maid Kuro-kun Ova

Given the content, major western streaming services like Crunchyroll or Funimation don't host it. In Japan, the series was released on DVD and Blu-ray by Columbia Music Entertainment, which may be available through Amazon Japan. For a purely legal, official digital version, you may need to purchase a region-free DVD or Blu-ray that includes English subtitles.