[Androzani84]

Well for once, a character not named in the episode is named in the credits, namely, she’s known as Anosillus II, with the original Anosillus being a monster from the OG Gridman who was associated with music (he lived with the “computer world” of a synthesiser) and had elasticity powers. He didn’t look human, but he did have a humanoid female (specified in the original episode to be a Compoid, an inhabitant of the Computer World) partner who seemingly had something of a romance with him. Make your own conclusions.

I’ll also add that originally, the character would've been Anosillus III (since an evil knockoff of Anosillus had appeared in a later episode), before it was changed to Anosillus Jr. to make the relationship more explicit and then finally to the current name because “Jr” is more associated with male children.

And talking of music, two recognisable theme songs can be heard. The first being that Rikka listens to Die Hollen Polizei, the theme song to the director’s (and indeed, the studio’s) first anime series, Inferno Cop.

And later, the sad piano music Anosillus II plays to wake up Yuta is the theme song to the original Gridman the Hyper Agent, known as Yume no Hero (or as it became known batter as thanks to memes, Baby Dan Dan). The group that performed this show’s theme song Union did their own cover.