Moneyness should work both sides of the trade

JPKoning: The moment the BoJ reduces the rate on deposits it creates a hot potato; an asset with a below-market return that its owner is desperate to be rid of. Bank reserve managers will simultaneously try to sell off their BoJ deposits in order to get a better return in short term corporate and government debt. In aggregate, however, banks cannot get rid of reserves, which pushes the prices of these competing short-term assets up and their expected returns back in line with the return on balances held at the central bank, a process that continues until reserve managers are indifferent on the margin between owning BoJ deposits and short term corporate/government debt.

Now, JP, you forget that the seller of any asset also has to suffer negative rates on  his sales price.  So you have an asset, and the BOJ just dropped rates, you try and sell the asset only to suffer the same loss on the money received.