Damn this is good drama, elements were introduced earlier and now we get a fuller picture... I hope my two dumb fav girls can help Kirio get better and also find good things in life
A character having a sad backstory doesn't make a story a tragedy. If the story were just about Kirio losing his best friend, that could be called a tragedy, but this is just a slight detour to explain the lack of progress, not the crux of the story itself. Besides, Kirio's barely a character tbh
you could probably justify a drama tag but i imagine a tragedy tag wouldn't be added unless the official raws/those tags are also on the JP upload /site as well