崩壊 ほうかい系列 けいれつじゃなかったです
hōkaikeiretsujanakattadesu

Noun
Desu Copula

The polite, past negative form of 崩壊系列

1. Wasn't a collapse series.; Wasn't part of the collapse series.

Past/Perfective
Negative
Polite
Casual Register
Physics