Song Meaning
The narrator admits to a fleeting attraction to another girl, immediately framing it as a "daydream" or "fantasy." He reassures his primary love interest that she is his "real one," but confesses a desire for more emotional capacity, wondering "how much can fit" in his "love vessel." This internal conflict between his current feelings and his perceived limitations sets up the core tension.
This fantasy is quickly shut down by his partner, who "noticed the scheme" and "laughed," telling him to "stop dreaming silly dreams." The "Mousou Machine No. 3" becomes a metaphor for these unacted-upon fantasies, a machine that only "imagines" because "reality is timid" and he lacks the courage to act. He apologizes, explaining he just "wanted to cheat in spirit."
The lyrics then shift perspective, with the partner responding to his confession. She dismisses his "love vessel" as small, stating it's "already full" with her, and that he doesn't need to "do useless things." This highlights a contrast between his perceived need for more capacity and her view that his current love is already complete and sufficient.
Later, the narrator revisits the "Mousou Machine," which "breaks down again." He blames his partner for "always breaking it," suggesting she controls his fantasies and desires, likening her to a "queen" who "remotely operates" him. This leads to the idea of developing "Mousou Machine No. 4," a "stealth type" with enhanced "security" to prevent her from detecting his wandering thoughts, revealing a complex dynamic of desire, guilt, and perceived control.
Ultimately, the narrator reiterates that the "Mousou Machine" is just a fantasy, a "daydream" that lasts "a moment" before he reaffirms his enduring love. The lyrics effectively capture the internal struggle of desire versus commitment, using the "Mousou Machine" as a clever, self-deprecating device to explore these complex emotions without acting on them.