Kono Tsumibukaki Yoru Ni

The old family falling into ruin-the Seikanji family. The eldest son, Kunitaka, is by chance reunited with his childhood friend, Ryouichirou, the son of a servant. The pair were separated from each other by a trivial misunderstanding, and from their reunion, Kunitaka, leading a constrained life, seeks comfort in Ryouichirou, and is drawn to him.
However, Ryouichirou has a grave secret, one that is a matter of life and death. Kunitaka, upon knowing this, offers his body to Ryouichirou, trying to save him…