The connection between Spermmania and Hayase Miku seems to stem from Miku's involvement in content creation that sometimes touches on the Spermmania theme. This can range from playful jokes and wordplay during her streams to fan-made content that combines Miku's character with Spermmania humor. The exact nature of this connection can vary, but it appears that Miku's openness to engaging with her audience and participating in internet trends has contributed to her popularity.