the end is kinda heartbreaking cause they couldn't be together forever and the is no loophole at all for them to reunite. It's 1 lifetime they get together and the second couple didn't even have time to confess/fully realize their feelings before Seme died o(TヘTo)
plus his uke cant reincarnate to follow him and the poor baby never got to confess so Seme thought up until the end that he wasn't truly loved by anyone (┬┬﹏┬┬)
Love X Devil