i had this same problem, solution? to get a character route you must spend every day with said character. some characters you cant find on some days which means you have to interact with anothing character to find them, check the 'steam community tab' for any help with figuring out what character routes need you to be where ( im sure someone made one if not ill make one in like a week) the way to tell if you got the 'good ending' for a character is the song 'victory day' will play during the concert, bad ending... well... you die. ( to get a good ending you have to hang out with the same charater for chapter 1 and 2 you cant just switch up, i highly reccomend you get every charater ending there might or might not be another ending :D )
hope this helps
-Chaos