Nuki Doki! ~Tenshi to Akuma no Sakusei Battle~ by Grand Cru bourgeois - Adult Sex Game

Life is not easy for OYASh. Yamato spent his days bored
until one day angels and demons appeared before him.
Everyone was tired of their long feud, so people
were chosen as a third party in the peace negotiations.
And Yamato, of course, is the representative of the people. Contract signed,
pretty angel Sarah Mitra Ayrun left from the angels,
sexy demon Firika Miya Satan from demons. Strange, but very pleasant, the hero thought.
Soon Firika, in order to win the hero over to her side, had sex with him.
The angel Sarah who flew in after fell into a trap and lost her virginity.
Thus, Yamato dragged the human world into a depraved confrontation between demons and angels!
What is the fate of the hero, surrounded by four beautiful girls?