1. move out room talk to fake sister, with him to assembly hall talk to priest
2. kitchen talk to sister in middle (2nd choice)
3. library talk to sister in upper (2nd choice)
4. east repentance room talk to sister in right (1st choice)
5. get 2 job in assembly hall
6. at night, room talk to sister , choice 3rd one 焼肉定食
7. east side upper right room talk to fake sister (red )
8. back to room, right table get drink then sleep (1st choice x2)
9. Day 2, to middle corridor (2nd choice) then go to kitchen can get power up item
10. talk to sister who near church entrance (1st choice) then get job in assembly hall
11. night, east side upper left room talk to sister (1st choice x2) (orange )
12. to fake sister room talk to him (all choice), then talk to him again
13. at night get drink then sleep (1st choice x2), outside talk to priest, with him go east to repentance room for H
14. Day 3, to middle corridor (2nd choice) then go to kitchen again can get power up item
15. get job in library or repentance room
16. at nigth sleep (1st choice x2), outside talk to priest, with him go east to repentance room for H
17. Day 4, to middle corridor (2nd choice) then go to library can get equip
18. get job in library or repentance room
19. at nigth sleep (3rd choice)
20. Day 5, to middle corridor (2nd choice) then go to repentance room can get $
21. get any job, at night go fake sister room talk to him, with him move out room talk to sister (yellow )
22. go assembly hall and click

Yes, you need to beat each boss to continue story. To beat him you should up near to lvl 20 and always use protect spell. The longer the fight, harder the boss will be.