Comiket (Japan’s fan convention) produces thousands of unlicensed doujinshi anime shorts. A fan group may have created a 5-minute OVA called Himawari wa Yoru ni Saku that never aired on TV. Toonhub4u might have ripped this from NicoNico or Bilibili.
Toonhub4u typically uses embedded video players with download options: Download - -Toonhub4u- Himawari wa Yoru ni Sak...
Target File: Himawari wa Yoru ni Saku (Sunflower Blooms at Night) – likely a fan-dubbed or obscure OVA/adult anime title. poetic anime about a night-blooming sunflower
Since the title does not exist officially, here are the three most likely possibilities for the file you are seeking: here is the safe protocol:
If you want to watch or download a rare, poetic anime about a night-blooming sunflower, here is the safe protocol: