Chidren with unfettered online access were exposed to "inappropriate content" and could suffer from cyber-harassment or experience changes to their sleep patterns, the government said.
Takaichi, an admirer of former British prime minister Margaret Thatcher, said before becoming premier that she wanted "Nordic" levels of gender balance in her cabinet.
A close eye will be kept on how many countries respond to Colombia's invitation to the first international conference on phasing out fossil fuels in April.