Uhhh

he did.

but they died

are you sure about this?

yes, although he regained his memory at the very end, in the epilogues there is no continuance of that last scene, except it only being a “more in depth” scene of jooha waking from his coma (no memories & still calling dooshik ahjussi) and the last panel was dooshik saying something along the lines of “i will always make sure he is happy and happiness is the only thing he experiences.” so, even though we dont have an answer, its clear to say they died as we wont get anything any further then this.