Complex sentence: Holiday-themed sequel originally released in Japan at Comiket 81; though the four main story scenarios and bonus features were originally released periodically via game patches in the Japanese release, all content from the completed game is included in the English release.
Split into simpler sentences: Holiday-themed sequel originally released in Japan at Comiket 81. The four main story scenarios and bonus features were released periodically via game patches in the original Japanese release, however all associated content is included in the English release.