Here’s a developed review of the OVA Himawari wa Yoru ni Saku (also searchable as Sunflower Blooms at Night or Sunflower Ha Yoru New), based on the premise and themes suggested by the title.
As of this article's publication, the OVA has not been released. However, based on standard OVA distribution models, here is where you will likely find it:
Keyword tip: Set a Google Alert for "Himawari wa Yoru ni Saku" OVA release date to catch the "new" announcement the moment it drops. himawari wa yoru ni saku ova sunflower ha yoru new
While no official trailer has been released by major studios like Kyoto Animation or Madhouse (as of this writing), aggregated fan translations suggest the following plot:
In a city that never sees the sun due to an eternal, crimson sky, a boy named Kai tends to a dying garden. He discovers a single sunflower seed buried in the ashes of the old world. A mysterious girl, Yoru (literally "Night"), appears only after dusk. She claims she can make the flower bloom, but only if Kai agrees to exchange his "memories of daylight." As the sunflower grows in the dark, Kai realizes that Yoru is not human—she is a spirit of lamentation, and the blooming flower will open a gate to a world that should have been forgotten. Here’s a developed review of the OVA Himawari
This Gothic romance meets ecological horror premise is why the search term includes "himawari wa yoru ni saku" (The sunflower blooms at night) and "sunflower ha yoru" (a common grammatical mis-typing of "wa" as "ha").
Because of the rural setting, time loops, and a girl named "Yoru" (an anagram of Ryu? Unlikely), some believe this is a new entry in the When They Cry franchise. However, Ryukishi07 has not confirmed this. Where to Watch (When It Releases) As of
For the uninitiated, Himawari wa Yoru ni Saku began as a dark fantasy doujinshi (self-published manga) in the late 2010s, created by the reclusive artist known only as Yoru no Hanakage (Night Flower Shadow). The title is paradoxical: sunflowers (himawari) typically turn toward the sun, yet here, they bloom in darkness.
“A quiet, melancholic bloom in the dark.”