The ED of this song is like one of the old maybe 60’s or 70’s (or probably 50s) Japanese encouragement songs to cheer up salarymen and students to do their best.
The episode is for introducing the main cast and the main rabbit, who’s not quite fit for the construction business – no, the real one…Uh, wait, I meant, not the Italian style but the real one…Oh wait, what real one? They fight and and they demolish their work!
For me the only notable seiyuu is Kotono sama, and that’s it. The rest I’ve never heard of.
This could be some sort of satire of Japanese society where people just go all out but don’t think much. Or it’s just for fun without meaning.
I wouldn’t know. Moving on to the next show…