Some time after the events of the first series, a new enemy has launched a surprise attack on Sound Planet and caused mass destruction. With it already being too late to fight back, a trio of ninja resort to time travel to warn the populace and hopefully prevent the impending tragedy.
While you don’t have to watch the prequel to follow the new storyline, that is where most of the characters and their quirks are introduced and it may be a bit overwhelming to have them all appear at once. The two seasons aren’t much different, having the same style of comedy (situational) and a similar mix of music, everyday cheerful situations, and bursts of personal/relationship-based drama.
More Information:
aniDB
Crunchyroll
Fansub.co
Wikipedia
