It's the last week of August, when children who have spent their entire summer vacation slacking off suddenly realize with daunting dismay that they have piles of book reports and diaries left untouched, not to mention an art project they were supposed to start weeks ago.

Bad news for them and their parents trying to help them out: Their last-minute "trump card" to get all the homework done is no longer available.

Operators of major online shopping websites — Mercari, Rakuten and Yahoo Japan — each released a joint statement together with the education ministry on Wednesday announcing they will ban the sales of what appear to be the works of a niche, if increasingly rampant, business: homework-by-proxy.