In the original release of the game, the hidden ending that follows the optional final boss battle against Hasebe and Mami reveals that Spoiler:Kyoko and Misako are not actually Kunio and Riki's girlfriends, but rather are simply delusional stalkers, with Hasebe and Mami being the boys' real partners; Kyoko and Misako then angrily punch Kunio and Riki into the sky after being reminded of this. This was written as an inside joke regarding the Kunio-kun franchise's convoluted localization history, specifically the fact that River City Girls Zero (the only prior game where Spoiler:Kunio and Riki actually dated Kyoko and Misako) had not yet received an English localization at the time of this game's release. As River City Girls was developed with Western audiences in mind, the joke was thus meant to be that Spoiler:Kunio and Riki have no memory of a title that wasn't officially available for this game's target audience.

However, the esoteric nature of the gag and the plot holes it opened regarding the game's premise resulted in it generating backlash from players who were not in on it. Because of this, the game was updated on January 18, 2020, changing the secret ending so that Spoiler:Kunio and Riki go out for food with Kyoko and Misako, implying that the latter two actually are their partners.

Kyoko's flurry kick features her shouting "ora ora ora," referencing Jotaro Kujo's battle cry in the JoJo's Bizarre Adventure franchise. Kyoko's voice actor, Kira Buckland, is a noted fan of JoJo and previously voiced Reimi Sugimoto in the English dub of JoJo's Bizarre Adventure: Diamond is Unbreakable. Incidentally, Buckland would later go on to voice Jolyne Cujoh, whose battle cry is also "ora ora ora," in the English dub of JoJo's Bizarre Adventure: Stone Ocean.

In Crosstown, stars of the let's play web series Game Grumps, Arin Hanson and Ross O'Donovan, make a cameo where they can be seen together drawing on pads. Both Ross and Arin also voice characters in the game.