Night of Replicant

Tomoki is in love with his sempai, Sawaki. One day while at Sawaki's house, Sawaki's brother Atsuya, caught him jerking off while smelling Sawaki's shirt and afraid Atsuya would let the secret out, Tomoki avoids his sempai. Four years later, Sawaki is getting married and Tomoki is invited to the party and while his 'love' for Sawaki is still as strong as ever, another person has their eyes on Tomoki. It's Atsuya, the younger brother of Sawaki who wants to conquer Tomoki's heart... will he have success?