It's just an internet gag about how Abe influenced anime to promote reproduction, fighting againts the aging population of Japan. In Darling in The Franxx, there was a blatant message about " breeding is good, Japanese young adults should do it more ". So many people started to related this show to that Shinzo Abe meme. Shinzo Abe did not do it. It's just Japanese anime industry has bunch of hacks.