だいとうみんねずみでわありませんでした
大冬眠鼠ではありませんでした
daitōminnezumidewārimasendeshita

Noun
Desu Copula

The polite, past negative form of おおやまね

1. Was not a hibernating mouse.; Was not a great hibernating mouse.

Past/Perfective
Negative
Polite
Formal Register
Usually Written in Kana