ใฉใใชใณใน means โlabyrinthโ or โmaze,โ a dramatic loanword that evokes mystery, confusion, and being unable to find your way out.
In the song, the narrator says he has been drawn into a ใฉใใชใณใน by the womanโs playful gestures, using the maze as a metaphor for their complicated and irresistible relationship.
Janne Da Arc's "Lunatic Gate" is a song about a man who knows exactly what this relationship is and still can't walk away. He opens on her eyes, "ๅทใใๅใฎ็ณ" (your cold eyes), which he says are "็ธๅคใใใ็กๆฉ่ณชใชๅฎ็ณใฟใใ" (as always, like an inorganic jewel). She looks down on men, yet she's very good at ไธ็ฎไฝฟใ (glancing up through her lashes, the cute upward look). When he starts talking about "ๅใฎๅฝผๅฅณ๏ฝ" (my girlfriend...), she pretends not to hear and "ๅใฎๅฃๅใซใใฟใคใใฆๆฅใ" (bites at my lips). So he's not exactly faithful either. His big promise is to take her to the "Lunatic Gate" and "ไฝใ้ ใใฆใใใฎๆ ้ใใฆใฟใใฆ" (open that door you're hiding something behind). The gift scene is blunt and a bit much: he buys her a low-cut dress not "็ใใใใใ" (because I want you to wear it) but because he wants to take it off her.
Then it turns. Seeing her outside in daylight throws him: "ๆ้ใใ ๅคช้ฝใฎไธใฎๆนใ ไผผๅใใใใฆใๅใ ่ฆใคใใใใชใใฎใฏใชใ?" (why can't I look at you, when you suit the sunlight far more than the dark?). He feels led into a ใฉใใชใณใน (labyrinth) and steered by her "ใใใใใช" (mischievous) little gestures. She wakes up in his arms knowing it's a "ใคใใฟๆใฎใชใ้ขไฟ" (a relationship with nothing to hold on to), and he spots "ไนพใใๆถใฎ่ทก" (traces of dried tears) under her forced smile. His line "ใใพใๅใใคใใฆ" (lie better) is cold, and it's the best moment in the song, because he admits right after that he used to prefer nights alone and now finds himself "ๅใฎๆ่งฆใใใใใฆใ" (searching for the feel of you).