User blog comment:TSRITW/THP Chapters/@comment-39868115-20200319095431/@comment-25612966-20200319100042

Bonus Chapters, which can be unlocked after completing their respective character's route.

Chapter B1 can be unlocked by completing the Main Route, B2 for Phil's, B3 for Boogaloo's, and so on.

Chapter B17, Tag's one and only chapter, can be unlocked after completing all sixteen routes.