Fool Night, Vol. 9 by Kasumi Yasuda

In a distant future where the sun no longer shines, Toshiro Kamiya gives up his body to a sinister floral metamorphosis for a payday. The earth of the distant future is covered in thick clouds, and the sun no longer shines. Plants wither, and oxygen is thin.

To fight extinction, humankind has developed a technology that turns humans into plants, providing a small amount of oxygen. Is this process sustainable? Is it ethical? Toshiro Kamiya must consider these questions as he’s faced with a difficult choice—save his family or save himself. After a violent battle with Ivy, Transflora Medical enjoys a brief period of peace.

However, Hourai has been enlisted by Dr. Kudai to find the scientist who transflorated Toshiro, and while pursuing that mystery, she uncovers several shocking new truths…