Also known as: 魔女集会で会いましょう, 魔法使い集会で会いましょう
"An Encounter with Witches". The male version translates to "An Encounter with Wizards", and the gender neutral "An Encounter with Magicians".
An online meme concerning witches (sometimes wizards as well) meeting a child that they end up raising. Almost always ends in the kid becoming their beautiful/handsome charge, or in some cases their lover, protector, or familiar.