Edit: I am an idiot that missed some of the requirements. Big thanks to
Mozenrak for bringing them to my attention.
Guide to achieve the Good ending:
0) You must talk to Leila (blond-haired Red Collar) in dormitory after you win couple of fights (duels or money matches - no matter), and you must do it BEFORE day 6. (You shouldn't miss it if you interact with dormitory constantly, she has a question mark above her head).
1) Beat all of duelists up to day 19.
2) In red light district map AT MIDNIGHT go to the top-left corner and catch your red-headed roommate, after that talk with her at the dorm, and catch her in the district again and stop them. After that she will become your friend.
3) From day 15 onward meet little succubus AT MIDNIGHT town gate, in the main plaza.
4) On DAY 20 EXACTLY have a breakfast with the girls in the dormitory. (Hard to miss unless you are ignoring the dormitory, talk to the white haired girl).
5) From day 20 onward you should meet the succubus and one-eyed old man in the red light district. (The guy is the one who kicked your ass in the intro, the Boss). Just walk upwards and talk to the girl with the question mark.
6) After that you MUST come into the left room in the colosseum near the molester who groped Sachi every day (the guard will give you way) and talk to Roro (cape person).
