So what does washing a pool have to do with being an idol?

b4z73rd said:

So what does washing a pool have to do with being an idol?

Free child labor.

Twintail Nao should be a thing more often.

b4z73rd said:

So what does washing a pool have to do with being an idol?

As a production publication event

Syoko, you weirdo! You really are the cutest thing sometimes!

The stated (in-world) point is the same as for events like idol sports days and such: to give fans a glimpse of their favorite idols doing "normal" things like participating in school events. (And I think they want that so the fans are less likely to stalk/crash their actual school events.)