So Mieru is Marissa and the childhood friend is Reimu...
Well, Mieru isn't a kleptomaniac, and Reimu isn't usually portrayed as being openly breast-envious*, nor does she have a Kansai accent.
(*There's the [in]famous Suika "can't-hear-yoo-over-the-sound-of-mah-tits" comic and Reimu's many interactions with 2P Miko, but even then Reimu is more subtle and private with her grudges.)
Mikoto here takes every slight (imagined or otherwise) to her 'assets' like Edward Elric does with height jokes (again, imagined or otherwise). Mieru calls her a "flatty Miss Miko" to provoke her and lure her out, Mikoto hears it as "chopping board pipsqueak squirt miko".
(Or "cuttin' board whippersnapper runt miko", since she's speaking in the Kansai dialect.)
Well, Mieru isn't a kleptomaniac, and Reimu isn't usually portrayed as being openly breast-envious*, nor does she have a Kansai accent.
(*There's the [in]famous Suika "can't-hear-yoo-over-the-sound-of-mah-tits" comic and Reimu's many interactions with 2P Miko, but even then Reimu is more subtle and private with her grudges.)
Mikoto here takes every slight (imagined or otherwise) to her 'assets' like Edward Elric does with height jokes (again, imagined or otherwise). Mieru calls her a "flatty Miss Miko" to provoke her and lure her out, Mikoto hears it as "chopping board pipsqueak squirt miko".
(Or "cuttin' board whippersnapper runt miko", since she's speaking in the Kansai dialect.)
The complex of RJ with the tsukkomi of ZKK
HEEEY!WE ARE CLOSED FOR THE DAYNobody's around...And we're here...MIKO-CHAAAAN!
YOU IIIIIN?The shrine we're going to, see?
It's my childhood friend's house!Shrine and Miko-sanShe's called Mikoto-chan, and she can see youkai!We've been fast friends ever since we were kids!Childhood friend?Hmm?...not coming out, eh?Flatty Miko-saaan.No, I didn't go quite that far.You wanna get gutted or somethin'!?WHO YOU CALLIN' A CHOPPIN'-BOARD RUNT OF A MIKOOOOOOOO!!!?