Watashi ni Saku Hana o Mite Kare wa Waratta [Seishin≠Genjitsu]

What's the "Truth"? Is there anything absolute in this world? If you're tired of abstract answers, welcome to this world of thought, reality and science. This is a philosophical story with horror elements told from one boy's and one girl's perspective during later half of Showa period.

[From vndbreview]