ますのすけじゃありませんでした
鱒の介じゃありませんでした
masuno sukeja arimasendeshita

Noun
Desu Copula

The polite, past negative form of ますのすけ

1. Was not Masunosuke.; Was not the person named Masunosuke.

Past/Perfective
Negative
Polite
Terminal Form
Usually Written in Kana