I saw the cover of the manga and it also had "Fleur, Mensonge et Makoto" written on it, meaning "Flower, Lies and Makoto". While Hana may be the mc's name, I think it might be the literal "Flower" instead.
Man this is sad, because Hana knows she is lying to herself and just trying to be happy, trying to replicate a past happiness and pretending Makoto's existence will last a bit longer...
Anyway I was just glad to find out what "Uso" meant and wanted to share