This anime is a triangle love story between Hazuki, a part-time in a flower shop, Shimao Rokka, the owner of the shop, and Shimao Atsushi - Rokka's late husband.
When Atsushi died due to illness, Rokka wished not to be left alone, and he wants to keep that promise. Now, as Hazuki is the only one who can see him, he tries to hinder him in his relationship with Rokka.
Hazuki with that kind personality is one of the most lovable characters ever! Somehow I can understand Atsushi too, as he got stuck as a ghost, and for an eternal life form moving on should be harder.
But Rokka... I seriously would want to kick a woman like that. He wouldn't give a chance to Hazuki cause she loves, or even just wants him. Nope, it's because "that should be the normal flow of life...". ... Really, a (few) hard kick(s) to a 2D character. Is that much to ask?